Fuel Cell and Hydrogen Energy Association Recommended Standard Test Methods … · 2014. 3. 14. ·...

Fuel Cell and Hydrogen Energy Association

Recommended Standard Test Methods

for Fuel Cell Gasket Materials

Fuel Cell and Hydrogen Energy Association Recommended Standard Test Methods for Fuel Cell Gasket Materials

Copyright © 2011 by Fuel Cell and Hydrogen Energy Association

Published by:

Fuel Cell and Hydrogen Energy Association 1133 19th Street, NW, #947 Washington, DC 20036 USA Tel. 202-736-5738

www.fchea.org

http://www.fchea.org/

Table of Contents

Preface..........................................................................................................................................................5

Acknowledgements .......................................................................................................................................5

Gasket Focus Group .....................................................................................................................................6

1 Scope.....................................................................................................................................................7

2 Referenced Documents .........................................................................................................................7

3 Terminology – Definitions ......................................................................................................................7

4 Significance and Use .............................................................................................................................7

5 Test Conditions ......................................................................................................................................7

6 General Test Methods ...........................................................................................................................8

6.1 Compressive Stress Relaxation ..................................................................................................8

6.2 Compression Set .........................................................................................................................8

6.3 Low Temperature Compression ..................................................................................................8

6.4 Tension Testing ...........................................................................................................................9

6.5 Hardness......................................................................................................................................9

6.6 Chemical Resistance ...................................................................................................................9

6.7 Temperature Resistance and Air Aging.......................................................................................9

6.8 Brittleness Temperature ..............................................................................................................9

6.9 Out-gassing .................................................................................................................................9

6.10 Summary Chart of Key Properties and Test Methods...............................................................10

6.11 Other Testing Methods of Potential Interest for Specific Applications ......................................11

6.11.1 ASTM Methods......................................................................................................................11

6.11.2 UL Method.............................................................................................................................11

6.11.3 Compression Stress Relaxation............................................................................................11

6.11.4 Surface Adhesion ..................................................................................................................12

6.11.5 Outgassing ............................................................................................................................12

6.11.6 Extractables...........................................................................................................................13

7 Types of Gasket Materials ...................................................................................................................13

8 Gasket Materials Tested......................................................................................................................14

8.1 Dana EPDM...............................................................................................................................14

8.2 Michigan Adhesive MG4095-456 (FCM 456) Polyurethane Hybrid ..........................................14

8.3 Henkel Loctite® 5714™ Silicone ...............................................................................................14

8.4 Wacker Elastosil® RT 624, RTV-2 Silicone Rubber..................................................................15

8.5 Sample Gasket Preparation and Conditioning ..........................................................................15

8.5.1 Sample Conditioning .............................................................................................................15

8.5.2 Sample Preparation and Testing Chart.................................................................................16

9 Test Procedures and Results ..............................................................................................................17

9.1 Physical Property Testing..........................................................................................................17

9.1.1 Equipment .............................................................................................................................17

9.1.2 Laboratory Conditions ...........................................................................................................17

9.1.3 Test Methods.........................................................................................................................17

9.1.4 Test Matrix.............................................................................................................................19

9.1.5 Results – Summary Graphs ..................................................................................................22

9.1.6 Results – Summary Data Tables...........................................................................................25

9.1.6.1 Tensile Property Data Tables .......................................................................................25

9.1.6.2 Hardness and Compression Set Data Tables ..............................................................27

9.1.6.3 Dimension and Weight Change Data Tables ...............................................................30

9.1.7 Physical Property Test Observations (After 2,000 hours Exposure)....................................32

9.1.7.1 Tensile Strength, Strain, Modulus ................................................................................32

9.1.7.2 Shore A Hardness ........................................................................................................32

9.1.7.3 Compression Set ..........................................................................................................32

9.1.7.4 Weight...........................................................................................................................32

9.1.7.5 Dimension.....................................................................................................................32

9.1.7.6 Other Considerations....................................................................................................32

9.1.7.7 Summary of “Percent Change from Original Values” after 2,000 hours Exposure ......33

9.2 Fourier Transform Infrared Spectroscopy – Attenuated Total Reflectance...............................34

9.2.1 Equipment: ............................................................................................................................34

9.2.2 Test Method...........................................................................................................................34

9.2.3 Sample Sets ..........................................................................................................................35

9.2.4 ATR-FTIR Test Observations................................................................................................36

9.2.4.1 Michigan Adhesives FCM 456......................................................................................36

9.2.4.2 Wacker Elastosil® RT 624............................................................................................36

9.2.4.3 Dana EPDM..................................................................................................................36

9.2.4.4 Henkel Loctite® 5714 ...................................................................................................36

10 Bibliography......................................................................................................................................54

10.1 Journal Articles and Public Documents .....................................................................................54

10.2 Supplier Material Information Data Sheets................................................................................54

10.3 Availability of Documents and Standards ..................................................................................54

10.4 Supplier and Test Site Information ............................................................................................55

Preface

Gasket design and selection for Proton Exchange Membrane Fuel Cell (PEMFC) stacks has been implemented, for the most part, by individual manufacturers and not to any specific sets of standards.

The industry recognizes that gasket performance is integral to the successful long-term operation of the fuel cell stack. While incorporation of the gasket into the fuel cell stack assembly has not presented significant problems, the risk of leakage, material degradation and migration has been a major concern, since contamination of the ion exchange membrane (IEM) will result in significant reduction in performance and life-time.

Material selection concerns include out-gassing, degradation and extraction of the gasket’s material components, which may contribute to contaminant migration into the IEM. Another key concern is the potential for internal and/or external leakage of fuel cell reactant gases when gasket materials lose their compression-set capabilities, and thus lose their “sealing contact” with the adjoining substrates.

The Gasket Focus Group addressed these concerns by identifying, selecting, and using test protocols to evaluate various gasket materials and measure property change and material losses over a 2,000 hour time period.

After significant deliberation, the group determined that existing ASTM Methods could be used to evaluate material physical properties of gasket material candidates.

As an “evaluation exercise” of the test methods, the group selected and tested candidate materials with physical and material properties believed important for sealing the interface of the MEA and individual cells of a PEMFC stack.

This report is issued as a reference and resource document to provide “guidance” to the design community when selecting and evaluating gasket materials for PEMFC stacks.

Acknowledgements

The Gasket Focus Group acknowledges the following companies for supplying gasket materials for this report, and pre-treating the samples for testing and evaluation:

Dana Holding Corporation

Henkel Corporation

Seal Bond (formerly Michigan Adhesive Manufacturing)

Wacker Chemical Corporation

The Gasket Focus Group acknowledges the following companies for testing and evaluating the sample gasket materials:

Henkel-Loctite® Labs (Physical Properties)

Cerium Labs (Chemical Degradation Analysis)

Gasket Focus Group Robert Wichert – Technical Director, Fuel Cell and Hydrogen Energy Association Tony Blaine – Chairman, Gasket Focus Group

Tom Benjamin Shanna Knights

Sumeet Bhargava Tom Mancino

Rick Blunk Adrienne O’Connor

Ethan Brown Dan Posey

Michael Brown Kathy Schwiebert

Bill Chao Jennifer Smith

Tim Cheng Eve Steigerwalt

Dennis Curtin Meena Sundarenson

Huyen Dinh Mike Yandrasiti

Laurie Florence John Van Zee

Mike Hicks Brynne Ward

Recommended Standard Test Methods for Fuel Cell Gasket Materials

1 Scope

These test methods describe the procedures for determining properties of PEM fuel cell gasket materials and changes in their properties due to aging. As an exercise, several of the recommended test methods were selected for evaluating four sample gasket materials. The samples were “aged” during a 2,000 hour exposure protocol, and their properties evaluated, compared and summarized in this report.

2 Referenced Documents

ASTM Standards:

D156605a – Standard Terminology Relating to Rubber

D88300 – Standard Terminology Relating to Plastics

D604802 – Standard Practice for Stress Relaxation Testing of Raw Rubber, Unvulcanized Rubber Compounds, and Thermoplastic Elastomers

D643602 – Standard Guide for Reporting Properties for Plastics and Thermoplastic Elastomers

3 Terminology – Definitions

Gasket: a deformable material clamped between essentially stationary faces to prevent the passage of material through an opening or joint. (ASTM D1566)

Gasket Types

Dynamic: seals moving parts

Static: seals nonmoving parts (movement still occurs through vibration, shock, temperature changes, pressure changes, etc.)

Gasket Forms

Conventional compression pre-forms or cut forms. Sheets/Films applied to the parts either precut or cut-in-place and then cured with secondary radiation.

Formed-in-place (high viscosity mastic type). Liquids cured by activation once in place and exposed to a radiation source, i.e. microwave, heat, UV light, etc.

4 Significance and Use

A gasket is expected to create and maintain a seal for a specified lifetime, while remaining impervious to relevant liquids/gases and compatible with the specific environment in which it is used.

These methods provide procedures for evaluation and comparison of varying gasket materials. They do not specifically address designed parts.

5 Test Conditions

Specimens to be tested should be kept in a standard environment (23°C) for a minimum of 30 minutes prior to testing, unless alternate procedures are detailed in the specific test method or below.

All test results should indicate how the sample was molded and/or cured and how it was conditioned prior to the test.

6 General Test Methods

ASTM Standards:

D614797 – Test Method for Vulcanized Rubber and Thermoplastic Elastomer Determination of Force Decay (Stress Relaxation) in Compression

D39503 – Standard Test Method for Rubber Property Compression Set

D122903 – Standard Test Method for Rubber Property Compression Set at Low Temperatures

D41298ae1 – Test Method for Vulcanized Rubber and Thermoplastic Elastomer Tension

D224004e1 – Test Method for Rubber Property Durometer Hardness

D47198e2 – Standard Test Method for Rubber Property Effect of Liquids

D57304 – Test Method for Rubber Deterioration in an Air Oven

D74604 – Standard Test Method for Brittleness Temperature of Plastics and Elastomers by Impact

Other Methods:

Method for Determining Out-gassing Constituents of Gasket Materials

6.1 Compressive Stress Relaxation

ASTM D6147 – A specimen is compressed 25%, and the counterforce is measured at specified time intervals.

Use Method B with washer specimen per D6147 section 7.1.3.

Use caution when loading specimen and initial measurements since properties are rapidly changing during the first stage of testing.

During immersion tests, use the test fluid as a lubricant per D6147 section 9.2.

Report specimen details and method details (test conditions) per D6147 section 12.

Report stress relaxation as a percentage of initial counterforce.

6.2 Compression Set

ASTM D395 – A specimen is compressed 25% for a specified amount of time, and the change in final thickness is measured after removal of the compressive force.

Use a test specimen of a cylindrical disk cut from a prepared slab. Report dimensions if they do not conform to D395 section 5.2.1.

Use Method B (compression set under constant deflection).

Report specimen details and method details (test time and temperature).

Report compression set as a percentage of the original deflection.

6.3 Low Temperature Compression

ASTM D1229 – A specimen is compressed 25% and then subjected to low temperature, and the amount of recovery after release of the compression is measured at the test temperature. Specimen thickness is measured at 10 seconds and again at 30 minutes after removal of the compression.

Report specimen details and method details (test time and temperature).

Report compression set as a percentage of the original deflection.

6.4 Tension Testing

ASTM D412 – Use Method A, preferably with dumbbell specimens.

Testing shall be performed under standard conditions. Additional data obtained under varying temperature and humidity should be labeled as such.

Use a rate of grip separation of 500 mm/min. Additional data obtained with varying speed should be labeled as such.

Report specimen details and method details.

Report tensile yield stress and strain, ultimate tensile strength and elongation, and tensile set per D412 section 13.

6.5 Hardness

ASTM D2240 – Report results per section 10.

Specifically include a description of the specimen (puck, stacked layers, etc.) and curing and/or molding conditions.

6.6 Chemical Resistance

ASTM D471 – Measure changes in dimensions, mass, volume, mass extractables, tensile properties and hardness after immersion in selected fluid.

Report specimen details and test setup, including exposure fluid, temperature, and duration.

6.7 Temperature Resistance and Air Aging

ASTM D573 – Dumbbell shaped specimens are exposed to air at elevated temperatures for a known period of time. After exposure, mechanical properties are measured according to ASTM D412.

Report specimen details, exposure temperature and time, and changes in dimensions and mechanical properties.

Samples should not be touching during exposure. After aging, samples should be cooled at room temperature on a flat surface for 16–96 hours before testing.

6.8 Brittleness Temperature

ASTM D746 – Brittleness temperature is defined as the temperature at which 50% of specimens fail, not necessarily the lowest temperature at which the material may be used.

Report specimen details, sample type, dimensions, method details, test temperature, and number of failures per D746 section 13.

6.9 Out-gassing

The organic constituents which are released from the gasket material with heat can be analyzed using a GCMS coupled with an automated thermal desorption (ATD) unit. A small sample of gasket material (e.g. few tenths of a gram) should be placed in a clean ATD tube filled with adsorbent. The tube is heated to the desired temperature for the desired amount of time. A typical heating program would be 30 minutes at 100°C. The out gassing constituents are collected in the adsorbent, then reheated and injected into a GCMS for identification. Sample size and heating program should be reported along with constituents identified according to retention time and relative area.

6.10 Summary Chart of Key Properties and Test Methods Property Method Description Comments Definition Test SummaryCompression Stress Relaxation

ASTM D6147-97 Test Method for Vulcanized Rubber and Thermoplastic Elastomer - Determination of Force Decay (Stress Relaxation) in Compression

Method A compresses and measures force decay at test temperature, while Method B compresses and measures force decay at ambient temperature. Preferences: Method B, use washer specimen (per 7.1.3), use caution during loading and initial measurements, during immersion lubricate with test fluid

"When a constant strain is applied to a rubber sample, the force necessary to maintain that strain is not constant but decreases with time, this behavior is called stress relaxation" - From G. Spetz, Stress Relaxation Tests, Technical Report 98/1A synonym is "Force Decay"

A test specimen is compressed by 25%. It is kept under compression during exposure to the test environment. The counterforce is measured at time intervals.

Compression Set ASTM D395-03 Standard Test Method for Rubber Property - Compression Set

Method A = constant force, Method B = constant deflection, Preferences: Method B, use specimens of disks cut from molded slabs.

The residual deformation of a material after removal of compressive stress

Compression Set ASTM D1229-03 Standard Test Method for Rubber PropertyCompression Set at Low Temperatures

Compress 25% at RT, then place in freezer, report temperature used and amount of time in freezer, release clamp and measure recovery at low temp after 10s and 30 min.

Determines rubber material 's ability to recover after compression at low temperatures.

Mechanical Properties ASTM D412-98ae1 Test Method for Vulcanized Rubber and Thermoplastic Elastomer - Tension

Use Method A (dumbell specimen), report sample curing conditions, test temp.

Measures tensile strength, yield stress, tensile stress, and elongation.

A dumbbell is placed in the grips of a test machine capable of grip separation at precise rates. The grips separate unti l the dumbbell breaks.

Durometer ASTM D2240-04e1 Test Method for Rubber Property - Durometer Hardness

Report description of specimen (solid puck, stacked layers, etc.) and curing conditions if applicable

Indentation hardness A test specimen is indented with a specific geometry indentor. A scale displays the hardness level.

Environmental Resistance ASTM D471-98e2 Standard Test Method for Rubber Property - Effect of Liquids

changes in dimensions, mass, volume, mass extractables, mechanical properties after immersion in selected f luid.

A test specimen is exposed to a test environment, where the specimens are spaced apart from one another.

Environmental Resistance ASTM D573-04 Test Method for Rubber-Deterioration in an Air Oven

Determines the effect of elevated temperatures on rubber materials

Test specimen is subjected to increasing temperatures in an air oven over a period of time

Thermal D746-04 Standard Test Method for Brittleness Temperature of Plastics and Elastomers by Impact

Determines at what temperatures plastics become brittle

Test specimen is held by a torque wrench and immersed in a cold liquid bath

Miscellaneous tests of interest for which no suitable ASTM methods were found:outgassing GC-MS GM-MS, heat sample to 100°C for

30 minutes and analyze volatile organic compounds which are released

Instrument type and columns may vary between labs, important to specify time and temperature for true comparisons of materials

Volati le organic components which are l iberated with heat and time according to the test, method of comparing materials and identifying organic contaminants

A small sample of the gasket material (<1 g) is placed in a sample holder, heated in the GC-MS, and the volati le constituents are analyzed in the GC-MS column

Contamination metals test for trace metals - leach or digest in acid

Identify contaminants using ICP

Contamination ions test for anions and cations - leach test using deionized water

Identify contaminants using IC-MS

6.11 Other Testing Methods of Potential Interest for Specific Applications

6.11.1 ASTM Methods

D57204 – Standard Test Method for Rubber Deterioration by Heat and Oxygen

D79200 – Standard Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement

D88202 – Standard Test Method for Tensile Properties of Thin Plastic Sheeting

D114999 – Standard Test Method for Rubber Deterioration Surface Ozone Cracking in a Chamber

D133004 – Standard Specification for Rubber Sheet Gaskets

D141494 – Standard Test Methods for Rubber O-Rings

D143482 – Test Method for Determining Gas Permeability Characteristics of Plastic Film and Sheeting

D572599 – Standard Test Method for Surface Wettability and Absorbency of Sheeted Materials Using an Automated Contact Angle Tester

E2904 – Standard Practice for Using Significant digits in Test Data to Determine Conformance with Specifications

E96/E96M05 – Standard Test Methods for Water Vapor Transmission of Materials

E43291 – Standard Guide for Selection of a Leak Test Method

E47991 – Standard Guide for Preparation of a Leak Testing Method

E595* 93(2003)e2 – Standard Test Method for Total Mass Loss and Collected Volatile Condensable Materials from Out-gassing in a Vacuum Environment

E69199 – Standard Practice for Conducting an Inter-laboratory Study to Determine the Precision of a Test Method

E148802e1 – Standard Guide for Statistical Procedures to Use in Developing and Applying Test Methods

E155903 – Standard Test Method for Contamination Out-gassing Characteristics of Spacecraft Materials

F60703 – Standard Test Method for Adhesion of Gasket Materials to Metal Surfaces

6.11.2 UL Method

UL 94 Tests for Flammability of Plastic Materials for Parts in Devices and Appliances

6.11.3 Compression Stress Relaxation

Compression Stress Relaxation, an adaptation of ASTM D6147 for Vulcanized Rubber and Thermoplastic Elastomer, is used for Determination of Force Decay (Stress Relaxation) in Compression. The stress decay of polymer components under constant compressive strain is known as Compression Stress Relaxation. This test measures the sealing force exerted by a seal or O-ring under compression between two plates. It provides definitive information for the prediction of the service life of materials by measuring the sealing force decay of a sample as a function of time, temperature and environment.

The test apparatus used for Compression Stress Relaxation measurements is the Wykeham Farrance device. The device measures precisely the counterforce exerted by a specimen maintained at constant strain between two stainless steel plates inside the compression jig over a period of time. The decay force is then plotted against time to generate the stress-relaxation

curve. The instrument has a variety of jigs for accommodating test pieces of O-rings up to 100 mm OD. Various service environments, liquids, gases or a mixture of the two can be introduced into the stainless steel compression jig and maintained during aging and testing. A typical cross-sectional view of the compression jig is shown below.

Benefits & Applications of the Test • Aging under compression can be achieved in a wide variety of media • More closely resembles end use applications than traditional Compression Set test • Essential tool in problem diagnosis and failure analysis • Valuable screening tool regarding new compounds for gaskets, seals and O-rings

6.11.4 Surface Adhesion

Evaluation of surface adhesion of the Gasket Material to one or both of the sealing surfaces (MEA and/or bipolar plate) provides another method of testing to ensure that leaks will not occur. Although compression of the Fuel Cell Stack relies on mechanical forces, it is possible that a leak can occur if the gasket material separates from the substrate. This can also contribute to material migration. The recommended test is ASTM D1002-1.

To ensure there is consistency in testing, it is suggested that the lap shears be of corrosion resistant Steel A167 Type 302. Preparation of the lap shears, as explained in sections 7 and 8 of the ASTM procedure, is very important. The gasket material manufacturer should be contacted for recommended curing methods of the product used for the tests.

Sample conditioning as explained in section 8.5.1 should be used for all specimens.

The test data should be reported as the average of 3 samples tested at each condition, including a value for the “as made” sample. A total of 5 sets (each with 3 samples) will be required for the “as made” plus samples removed after 24, 168, 500, and 2,000 hours of exposure. The sets should be run to “load failure” as described in Procedure 9 of ASTM1002.

Reports should be issued following the guidelines in ASTM section 11.

For additional testing, it is possible to consider ASTM D3163-01.

6.11.5 Outgassing

The sensitivity to contaminants is becoming more important as the PEM fuel cell industry develops cost-effective designs that enable the fuel cell stack to be more competitive with alternative technologies. These “lower-cost” state-of-the-art membranes and electrocatalysts only will be successful if the effects of external deterrents to their durability and performance are kept to a minimum. Gasket materials that are "cured-in-place" or "formed-in-place" are known to outgas harmful volatiles during curing (e.g., solvents, cross-linking agents). In addition, fully cured gaskets can also emit species (e.g., low-molecular reaction products) that may negatively affect PEM health. Therefore, it is imperative to identify the type and concentration of potential contaminants using ex situ testing methods. This evaluation can involve measurement of volatile

organic content (VOCs) using an approach similar to ASTM D2369-10; or performing Thermogravimetric (TGA) analysis at simulated nominal fuel cell operating conditions.

6.11.6 Extractables

Fully-cured gasket materials may contain “filler materials” or other leachable components (e.g., metal ions from catalysts, organic content from plasticizers, adhesion promoters, etc.), which may be extracted when the gasket is in contact with typical fuel cell reactant streams or byproducts. Since the gasket materials can essentially act as "reservoirs" of such contaminants, and continuously leach such species over the entire lifetime of the fuel cell system, it is important to identify and evaluate the effects of all leachants using ex situ tests during the gasket material screening stage. Some of the recommended tests are listed below:

Tracking weight, volume and hardness change during long-term fluid immersion (Ref: http://www.hydrogen.energy.gov/pdfs/review09/fc_42_parsons.pdf, Slide 10)

Tracking surface tension, total organic carbon (TOC), total inorganic carbon (TIC), volatile organic content (VOC), pH, conductivity) during long-term fluid immersion (Ref: http://www.hydrogen.energy.gov/pdfs/review09/fc_42_parsons.pdf, Slide 11)

7 Types of Gasket Materials Gaskets Description (conventional Compression) Temperature RangePolyacrylate Rubber Polyacrylate rubber has excellent resistance to petroleum oils, oxygen, and ozone, but relatively poor low temperature flexibility

and water resistance. The primary use is in automotive engine oil and transmission fluid. 5 to +35°F

Ethylene Acrylate Rubber Ethylene Acrylate rubber, it is commonly used in transmission fluid, power steering fluid, and engine oil applications. It offers improved low temperature performance relative to polyacrylate, but it also swells more.

40 to +325°F

Butyl Rubber A copolymer of isoprene and isobutylene and referred to as IIR rubber under ASTM D1418, butyl rubber is known for extremely low permeability and very poor rebound resilience.

75 to +25°F

Neoprene Rubber Neoprene, or polychloroprene rubber, was the first synthetic rubber material. Because it offered significantly better oil resistance than natural rubber, it was the primary seal material for oil applications through WWII. Today, the primary use of neoprene is in refrigerant applications.

60 to +25°F

Ethylene Propylene Rubber

Ethylene propylene rubber, commonly called EPR or EPDM, offers outstanding resistance to polar solvents like acetone, alcohols, and MEK. It is not compatible with petroleum oils and greases.

70 to +25°F

Fluorosilicone Rubber Fluorosilicone rubber uses a silicon oxygen (siloxane) main backbone for excellent thermal stability and highly fluorinated side chains for oil and fuel resistance. Mechanical properties are generally poor, and fluorosilicone should not be used in dynamic applications

100 to +35°F

Nitrile Rubber Nitrile (a.k.a. NBR or BunaN) rubber is by far the most common type of seal material in the world. The nitrile functionality (carbon triple bonded to nitrogen) provides resistance to oils and fuels.

55 to +225°F

HNBR Rubber Hydrogenated nitrile (a.k.a. HNBR or HSN) is a "first cousin" to standard nitrile rubber, with the added benefit of being ozone resistant. It is primarily used in automotive refrigerants and high temperature hydraulics.

25 to +300°F

Urethane Rubber Thermosetting elastomeric urethane is chemically similar to thermoplastic urethane, but it looks and behaves more like nitrile rubber

40 to +18°F

Silicone Rubber Silicone rubber is commonly used in medical devices and hot air applications. The silicone oxygen (siloxane) main polymer backbone is very stable thermally, but prone to mechanical damage. As a result, silicone materials are not recommended for use in dynamic applications.

70 to +40°F

Fluorocarbon Rubber Because of its excellent chemical resistance and outstanding upper temperature limit, fluorocarbon rubber has become one of the most widely used seal materials in the world.

15 to +40°F

Metals Isoprene Butadiene Liquids Description (Cured in place) Temperature RangePolyurethanes Thermosetting elastomeric urethane is chemically similar to gaskets made from polyurethane. It is in liquid form and cures with

heat and time. Tendency to revert. 40 to 200°F

Silicones Thermosetting elastomeric silicones is chemically similar to gaskets made from silicones. It is in liquid form and cures with heat and time. Tendency to leach out cyclic.

70 to +40°F

Epoxies Thermosetting epoxies can be formulated from elastomeric to hard brittle solids, they come in a liquid form and cure with heat and time. Performance is extremely dependent on formulation.

185 to 400°F

Acrylates Thermosetting acrylates can be formulated from elastomeric to hard brittle solids, they come in a liquid form and cure with heat and time. Performance is extremely dependent on formulation.

40F to 200°F

Bismaleimides High temperature high reliability but may require high cure temperatures. Expensive 65 to 500°F Cyanoacrylate Cure with time or anaerobic conditions. Problems with reversion. Preforms Description (Cured in place) Temperature RangeEpoxies Thermosetting epoxies can be formulated from elastomeric to hard brittle solids, they come in a liquid form and cure with heat

and time. Performance is extremely dependent on formulation. 185 to 400°F

Acrylates Thermosetting acrylates can be formulated from elastomeric to hard brittle solids, they come in a liquid form and cure with heat and time. Performance is extremely dependent on formulation.

40F to 200°F

Bismaleimides High temperature high reliability but may require high cure temperatures. Expensive 65 to 500°F Polyesters Thermoplastic or thermoset forms. Thermoplastics capable of rework. May have reversion problems with humidity and

temperature. 50 to 200°F

Functionalized Polyolefins Limited temperature range, good resistance to heat. Permeability can be high. 185 to 200°F

http://www.hydrogen.energy.gov/pdfs/review09/fc_42_parsons.pdf


8 Gasket Materials Tested

8.1 Dana EPDM

EPDM rubber (ethylene propylene diene Monomer (M-class) rubber), a type of synthetic rubber, is an elastomer which is characterized by wide range of applications. The “M” class includes rubbers having a saturated chain of the polymethylene type. The diene(s) currently used in the manufacture of EPDM rubbers are DCPD (dicyclopentadiene), ENB (ethylidene norbornene) and VNB (vinyl norbornene). The ethylene content is around 45% to 75%. The higher the ethylene content the higher the loading possibilities of the polymer, better mixing and extrusion.

Peroxide curing these polymers gives a higher crosslink density compared with their amorphous counterpart. The amorphous polymers are also excellent in processing. This is very much influenced by their molecular structure. The dienes, typically comprising between 2.5 wt% up to 12 wt% of the composition serve as cross-links when curing with sulfur and resin, with peroxide cures the diene (or third monomer) functions as a co-agent, which provide resistance to unwanted tackiness, creep or flow during end use.

8.2 Michigan Adhesive MG4095-456 (FCM 456) Polyurethane Hybrid

Michigan Adhesive FMC 456 is a one component, multi-purpose adhesive/sealant designed for difficult bonding and sealing applications. While not specifically designed for fuel cell applications, this product is moisture-curing and was developed for industrial uses requiring a good balance of elasticity, high strength and excellent adhesion.

FCM 456 is supplied as a 100% solids paste, and is solvent and isocyanate free, non-flammable, fast curing, no odor, extremely low shrinkage, has a specific gravity of 1.6-1.7 and a shelf-life of 10 months in unopened containers stored between 60 and 80°F.

FMC 456 is tough, elastic and weatherproof; and is based on a unique polymer system that will cure at temperatures as low as 13ºF. It has excellent weathering characteristics and is suitable for use in all climates. FMC 456 provides primer-less adhesion to steel, aluminum, ceramics, coated metal, glass, and many plastics (Acrylic, Polycarbonate, ABS, PVC, Styrofoam®).

Approximate Performance Properties (after 7 day ambient cure)

Shear Strength 185 psi ASTM D-1002 Tensile Strength 225 psi ASTM D-412 Elongation at Break 370 % ASTM D-412 Hardness Shore A 53 (14 day ambient cure) ASTM C-661 Slump (Sag) Zero Slump ASTM C-639 Flame Spread/Smoke 0 Flame / 0 Smoke ASTM E84-00a Tack Free Time 20 minutes ASTM C-679 Low Temperature Flex -20ºF ---PASS--- Stain Testing No Staining Service Temperature -40º to 200º F, temporarily resistant to 390º F.

Note: Michigan Adhesive now operates under the Seal-Bond corporate name.

8.3 Henkel Loctite® 5714™ Silicone

Loctite® 5714™ is a two component, heat curing, liquid injection molding silicone designed for creating compression seals on bipolar plates, membrane electrode assemblies and other components used in the fabrication of a proton exchange membrane fuel cell (PEMFC). After curing, the sealant functions as a compression gasket, which enables it to make the required gastight seal. Loctite® 5714™ is a low ionic formulation that has been specially formulated to be compatible with the membrane electrode assemblies (MEA's). The product was designed for fast cure enabling and fast cycle times in Liquid Injection Molding (LIM) processes.

8.4 Wacker Elastosil® RT 624, RTV-2 Silicone Rubber

Characteristics

Pourable, addition-curing, two-component silicone Rubber that vulcanizes at elevated temperature. Special characteristics High tear resistance Long pot life at ambient temperature High reactivity already at 100 °C Outstanding compression set Cure at low mold temperature possible Particularly high hydrogen resistance Application Silicone rubber for temperature sensitive sealing applications Particularly suitable for fuel cell seals

8.5 Sample Gasket Preparation and Conditioning

The Dana EPDM samples were provided as “sheet stock”.

The Michigan Adhesives PU sample and the Wacker and Henkel Silicone samples were cast and cured into “sheet stock” from liquid solutions. The four companies converted their own material candidates into sample sets, which were then sent to three of the companies to perform independent “aging” test. The result was three independently conditioned sample sets for each of the four gasket candidates. The preparation protocol produced three replicates for each condition and allowed examination of any “aging-effect” bias between the three locations performing the exposure protocol – providing a total of 60 samples for each gasket candidate – 4 candidates x 5 exposure times (0, 24, 168, 500, 2,000 hrs) x 3 “exposure” sites.

8.5.1 Sample Conditioning

Highlights on “aging” and test protocols: Three companies conditioned the four sets of gasket candidates in de-ionized (DI) water

maintained at 80°C, with the samples 100% submerged. Additional DI water was added to make-up for evaporation losses. All samples were in the same water container at each site.

Each test location performed the same “aging” protocol. Samples from each set were removed at 24, 168, 500, 2,000 hours of exposure. Each sample’s physical property and material chemistry changes were measured after each

exposure time-period and compared to the “as made” values.

8.5.2 Sample Preparation and Testing Chart

Michigan Adhesives

FCM 456 Polyurethane

Dana

EPDM

Wacker

Elastosil® RT624

Henkel

Loctite® 5714

Four Sample Sets Treated at Dana, Wacker and Henkel Sites

Exposure Times of 24, 168, 500 and 2000 hours in 80°C Demin Water

Henkel-Loctite® Test Lab

All Four SetsPhysical Property Testing

Cerium Labs

Same SetsChemical Surface Analysis

Sample Preparation and TestingFour Gasket Candidate Sets, Exposed at Three Sites,

and Evaluated by Two Test Labs

9 Test Procedures and Results

9.1 Physical Property Testing

The objective was to test all specimens that were conditioned under a separate procedure (submerged in 80°C DI Water for up to 2,000 hours). Testing included Hardness, Tensile and Elongation, Compression Set, Weight Change and Dimensional Change.

Analysts: Jamie Hubbard, Application Engineer Anne-Marie L. Noonan, Laboratory Operations Supervisor

Andrew Scott, Laboratory Technician Henkel Corporation One Henkel Way Rocky Hill, CT 06067 860-571-5100

9.1.1 Equipment

Instron® 30 kN Load Cell UK455 Instron® 5500R Instron® Load Cell 564 Instron® Extensometer 9 VWR Timer 6363 Fisher Timer 4261 Shore A Durometer 1311 Oven with Fluke Thermometer 4327G White Box Temperature/Humidity Recorder 3600 Dickson Thermo-Hygrometer Blue-M Oven ELMS Oven Monitoring System Mitutoyo Digital Caliper AND Digital Scale

9.1.2 Laboratory Conditions

Temperature 71°F (typical range: 70 +/- 2° F) Relative Humidity 52-53 % (typical range: 50 +/- 10 %)

9.1.3 Test Methods

The following Loctite® standard test methods were used to measure the physical properties, which Henkel’s Rocky Hill Engineering and Testing Laboratory is accredited to perform per ISO 17025. Loctite® Method 707 based on ASTM D 2240 (1/20/2006):

Shore A hardness was done in accordance with ASTM D 2240. Films of material (1 in by 3 in) were made and stacked in order to meet the ¼ in thick

sample requirement. Loctite® Method 708 based on ASTM D 412/471 (2/14/2003):

Tensile, elongation, modulus was performed in accordance with ASTM D 412 and D 471. Data for an overall “stress-strain curve” was not collected during this test.

The sample strain rate was 20 in/min, with Young’s Modulus measured in the proportional (initial) strain region.

Dumbbell Die C was used to create dog bones from cured films.

Loctite® Method 747 based on ASTM D 395; Method B (6/7/2007):

Compression set was performed in accordance with ASTM D 395; Method B. This method measures the permanent deformation remaining after release of a compressive stress. Compression set is expressed as the percentage of the original deflection.

Samples were cut from cured films of each candidate. Each specimen was compressed 25% for 22 hours at 80°C. Compression set is taken as

the percentage of the original deflection after the material is allowed to recover at standard conditions for 30 minutes.

The compression set (Method B) was calculated using the following equation:

%100)/()( noioB ttttC

where to is the original specimen thickness, ti is the specimen thickness after testing, and tn is the spacer thickness.

Compression set is an important property for elastomers and sealing materials, and is an indicator of the materials ability to maintain a sealing force against a substrate. A low or “zero” value is preferred.

The compression set data for the samples are reported on a summary chart and in tabular format.

Weight Change Method

Each material’s dimensional change (length, width, thickness) was studied to determine the effect of soaking in 80°C de-ionized water for a specified time period.

An oven was set to 80°C, and a metal tank filled with deionized (DI) water was placed in the oven.

Each sample’s initial weight was recorded, and then the samples were suspended in the water-filled tank for the time shown in the experimental test matrix.

The samples were removed at selected exposure times, carefully cleaned using reagent grade water having 18 M resistance, and air-dried at room temperature for two hours before the weight change was measured.

The percent weight change was calculated using the following equation:

%1001

12 xW

WWgeWeightChan

where W1 (W2) is the weight of the sample before (after) exposure. The weight change data for the samples are reported on a summary chart and in tabular

format. Both weight loss and weight gains are considered “negative” responses, with the ideal

candidates having little or no weight change for the exposure time periods.

Dimensional Change Method Each material’s dimensional change (length, width, thickness) was studied to determine

the effect of soaking in 80°C de-ionized water for a specified time period. An oven was set to 80°C, and a metal tank filled with deionized (DI) water was placed in

the oven. Each sample’s “as made” dimensions were measured, and then the samples were

suspended in the water-filled tank for the time shown in the experimental test matrix.

The samples were removed at selected exposure times, carefully cleaned using reagent grade water having 18 M resistance, and air-dried at room temperature for 2 hours before the dimensional changes in length, width and thickness were measured.

The dimensional change data for the samples are reported in tabular format. Dimensional change is considered a “negative” response, with the ideal candidates

having little or no “swelling” or “shrinkage” for the exposure time periods. Note: all films for each test were cured for a minimum of seven days at standard laboratory conditions.

9.1.4 Test Matrix

Experimental Test Matrix Exp Sample Hours Test Replicates

1 Wacker RT 624 0 Hardness, Shore A 5 2 Wacker RT 624 24 Hardness, Shore A 5 3 Wacker RT 624 168 Hardness, Shore A 5 4 Wacker RT 624 500 Hardness, Shore A 5 5 Wacker RT 624 2,000 Hardness, Shore A 5 6 Wacker RT 624 0 Tensile, Modulus,

Elongation 5

7 Wacker RT 624 24 Tensile, Modulus, Elongation

5


5


5

10 Wacker RT 624 2,000 Tensile, Modulus, Elongation

5

11 Wacker RT 624 0 Compression Set 3 12 Wacker RT 624 24 Compression Set 3 13 Wacker RT 624 168 Compression Set 3 14 Wacker RT 624 500 Compression Set 3 15 Wacker RT 624 2,000 Compression Set 3 16 Dana EPDM 0 Hardness, Shore A 5 17 Dana EPDM 24 Hardness, Shore A 5 18 Dana EPDM 168 Hardness, Shore A 5 19 Dana EPDM 500 Hardness, Shore A 5 20 Dana EPDM 2,000 Hardness, Shore A 5 21 Dana EPDM 0 Tensile, Modulus,

Elongation 5

22 Dana EPDM 24 Tensile, Modulus, Elongation

5


5


5

25 Dana EPDM 2,000 Tensile, Modulus, Elongation

5

26 Dana EPDM 0 Compression Set 3 27 Dana EPDM 24 Compression Set 3 28 Dana EPDM 168 Compression Set 3


29 Dana EPDM 500 Compression Set 3 30 Dana EPDM 2,000 Compression Set 3 31 Michigan Adhesives FCM 456 0 Hardness, Shore A 5 32 Michigan Adhesives FCM 456 24 Hardness, Shore A 5 33 Michigan Adhesives FCM 456 168 Hardness, Shore A 5 34 Michigan Adhesives FCM 456 500 Hardness, Shore A 5 35 Michigan Adhesives FCM 456 2,000 Hardness, Shore A 5 36 Michigan Adhesives FCM 456 0 Tensile, Modulus,

Elongation 5

37 Michigan Adhesives FCM 456 24 Tensile, Modulus, Elongation

5


5


5

40 Michigan Adhesives FCM 456 2,000 Tensile, Modulus, Elongation

5

41 Michigan Adhesives FCM 456 0 Compression Set 3 42 Michigan Adhesives FCM 456 24 Compression Set 3 43 Michigan Adhesives FCM 456 168 Compression Set 3 44 Michigan Adhesives FCM 456 500 Compression Set 3 45 Michigan Adhesives FCM 456 2,000 Compression Set 3 46 Henkel Loctite® 5714 0 Hardness, Shore A 5 47 Henkel Loctite® 5714 24 Hardness, Shore A 5 48 Henkel Loctite® 5714 168 Hardness, Shore A 5 49 Henkel Loctite® 5714 500 Hardness, Shore A 5 50 Henkel Loctite® 5714 2,000 Hardness, Shore A 5 51 Henkel Loctite® 5714 0 Tensile, Modulus,

Elongation 5

52 Henkel Loctite® 5714 24 Tensile, Modulus, Elongation

5


5


5

55 Henkel Loctite® 5714 2,000 Tensile, Modulus, Elongation

5

56 Henkel Loctite® 5714 0 Compression Set 3 57 Henkel Loctite® 5714 24 Compression Set 3 58 Henkel Loctite® 5714 168 Compression Set 3 59 Henkel Loctite® 5714 500 Compression Set 3 60 Henkel Loctite® 5714 2,000 Compression Set 3 61 Wacker RT 624 24 Weight Change 3 62 Wacker RT 624 168 Weight Change 3 63 Wacker RT 624 500 Weight Change 3 64 Wacker RT 624 2,000 Weight Change 3 65 Dana EPDM 24 Weight Change 3 66 Dana EPDM 168 Weight Change 3 67 Dana EPDM 500 Weight Change 3


68 Dana EPDM 2,000 Weight Change 3 69 Michigan Adhesives FCM 456 24 Weight Change 2 70 Michigan Adhesives FCM 456 168 Weight Change 2 71 Michigan Adhesives FCM 456 500 Weight Change 2 72 Michigan Adhesives FCM 456 2,000 Weight Change 2 73 Henkel Loctite® 5714 24 Weight Change 3 74 Henkel Loctite® 5714 168 Weight Change 3 75 Henkel Loctite® 5714 500 Weight Change 3 76 Henkel Loctite® 5714 2,000 Weight Change 3

9.1.5 Results – Summary Graphs

Figure 1: Results of Shore A Hardness Testing after various Exposure Times

0

10

20

30

40

50

60

70

80

90

100

0 500 1000 1500 2000

Exposure Time [Hours]

Sh

ore

A H

ard

ne

ss

Dana

Henkel 5714

Michigan FCM456

Wacker RT 624

Figure 2: Compression Set after various Exposure Times

0%

20%

40%

60%

80%

100%

120%

0 500 1000 1500 2000

Time (hours)

Co

mp

ress

ion

Set

Fin

al (

%)

DANA

Henkel 5714

Michigan FMC 456

Wacker RT 624

Figure 3: Results of Tensile Modulus after various Exposure Times

0

200

400

600

800

1000

1200

1400

1600

1800

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time (hours)

Mo

du

lus

(psi

)

DANA in 80°C Water

Henkel 5714 in 80°C Water

Michigan FMC456 in 80°C Water

Wacker RT 624 in 80°C Water

Figure 4: Results of Tensile Strength after various Exposure Times

0

200

400

600

800

1000

1200

1400

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time (hours)

Ten

sile

(P

SI)

DANA in 80°C Water


Michigan FMC 456 in 80°C Water


Figure 5: Results of % Elongation after various Exposure Times

0

50

100

150

200

250

300

350

400

450

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time (hours)

Str

ain

@ M

ax L

oad

(%

)

DANA in 80°C Water


Michigan FMC 456 in 80°C Water


Figure 6: Weight Change after Submersion in DI Water @ 80°C

-4%

-2%

0%

2%

4%

6%

8%

10%

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time, hrs

Wei

gh

t %

Ch

ang

e Loctite 5714 (Silicone)

Wacker RT 624 (Silicone)

Dana (EPDM)

Michigan Adhesives FCM-456(PU)

9.1.6 Results – Summary Data Tables

9.1.6.1 Tensile Property Data Tables

Table 1: Henkel Loctite 7514 -- Tensile Properties

Exposure Time

Statistics Strain

at Max Load (%)

Stress at Max Load

(psi)

Modulus (Young’s)

(psi)

Average 322 257 159 Std. Dev. 14.7 7.8 12.1

COV 0.05 0.03 0.08 0 Hours

in 80°C DI H2O

Minimum 304 249 149 Average 328 257 155 Std. Dev. 17.1 15.5 15.6

COV 0.05 0.06 0.10 24 Hours

in 80°C DI H2O

Minimum 312 238 126.8 Average 335 267 147 Std. Dev. 23.7 27.4 28.3

COV 0.07 0.10 0.19 168 Hours

in 80°C DI H2O


COV 0.04 0.04 0.00 500 Hours

in 80°C DI H2O

Minimum 340 279 116 Average 402 191 69 Std. Dev. 101 38 18

COV 0.25 0.20 0.26 2,000 Hours

in 80°C DI H2O

Minimum 266.4 140.3 49.4

Table 2: Dana EPDM -- Tensile Properties

Exposure Time

Statistics Strain

at Max Load (%)

Stress at Max Load

(psi)

Modulus (Young’s)

(psi)

Average 127 1119 1600

Std. Dev. 8.1 101.2 204.2

COV 0.06 0.09 0.13 0 Hours

in 80°C DI H2O

Minimum 116 1017 1387

Average 125 1117 1595

Std. Dev. 6.7 97.1 99.7

COV 0.05 0.09 0.06 24 Hours

in 80°C DI H2O

Minimum 118 991 1501

Average 117 998 1366

Std. Dev. 8.8 144.6 156.0

COV 0.08 0.14 0.11 168 Hours

in 80°C DI H2O

Minimum 106 820 120

Table 2: Dana EPDM -- Tensile Properties

Exposure Time

Statistics Strain

at Max Load (%)

Stress at Max Load

(psi)

Modulus (Young’s)

(psi)

Average 129 1159 1472

Std. Dev. 6.8 132.7 77.1

COV 0.05 0.11 0.05 500 Hours

in 80°C DI H2O

Minimum 118 966 1358

Average 108 805 1141

Std. Dev. 7.7 134.7 142.6

COV 0.07 0.17 0.12 2,000 Hours

in 80°C DI H2O

Minimum 102 702 1006

Table 3: Wacker RT 624 -- Tensile Properties

Exposure Time

Statistics Strain

at Max Load (%)

Stress at Max Load

(psi)

Modulus (Young’s)

(psi)

Average 362 770 287 Std. Dev. 28.3 66.1 5.6

COV 0.08 0.09 0.02 0 Hours

in 80°C DI H2O


COV 0.06 0.06 0.02 24 Hours

in 80°C DI H2O


COV 0.05 0.04 0.03 168 Hours

in 80°C DI H2O


COV 0.09 0.07 0.04 500 Hours

in 80°C DI H2O


COV 0.10 0.08 0.05 2,000 Hours

in 80°C DI H2O

Minimum 262 602 243 Note: All 2,000 hour test samples failed at an "air pocket".

Table 4: Michigan Adhesives FCM 456 -- Tensile Properties

Exposure Time

Statistics Strain

at Max Load (%)

Stress at Max Load

(psi)

Modulus (Young’s)

(psi)

Average 194 290 497

Std. Dev. 29.9 15.5 91.6 COV 0.15 0.05 0.18

0 Hours in 80°C DI H2O


COV 0.16 0.07 0.18 24 Hours

in 80°C DI H2O


COV 0.06 0.01 0.12 168 Hours

in 80°C DI H2O

Minimum 140 228 452

Average 185 237 683 Std. Dev. 9.9 17.6 136.4

COV 0.05 0.07 0.20

500 Hours in 80°C DI H2O


COV 0.08 0.20 0.26 2,000 Hours

in 80°C DI H2O

Minimum 167 84 122

9.1.6.2 Hardness and Compression Set Data Tables

Table 5. Durometer Shore A Hardness Test Results Gasket Material Candidates Exposure

Hours Henkel 5714 Dana EPDM Wacker RT 624 Michigan FCM 456

0 30 70 39 52 24 30 69 38 51

168 30 69 39 50 500 30 70 41 49

2,000 15 69 41 27 Final Loss 50.0% 1.4% 0.0% 48.1%

Table 6: Wacker RT 624 -- Compression Set (STM-747)

Exposure Time (hrs)

Statistics Specimen Initial

Thickness (in)

Spacer Bar Thickness Used (in)

Specimen Thickness Final (in)

Compression Set Final

(%)

Average 0.490 0.365 0.493 0.0% 0

Std. Dec. 0.000 0.000 0.005 0.0% Average 0.495 0.370 0.492 2.6%

24 Std. Dec. 0.018 0.013 0.014 4.4% Average 0.500 0.375 0.500 0.0%

168 Std. Dec. 0.000 0.000 0.000 0.0% Average 0.475 0.355 0.475 0.0%

500 Std. Dec. 0.005 0.005 0.005 0.0% Average 0.476 0.355 0.455 17.3%

2,000 Std. Dec. 0.002 0.000 0.006 5.6%

Table 7: Henkel 5714 -- Compression Set (STM-747)

Exposure Time (hrs)


Thickness (in)




(%)

Average 0.490 0.367 0.490 0.3% 0

Std. Dev. 0.005 0.003 0.005 0.5% Average 0.483 0.362 0.481 1.6%

24 Std. Dev. 0.006 0.003 0.003 2.1% Average 0.483 0.362 0.482 1.3%

168 Std. Dev. 0.006 0.003 0.003 2.3% Average 0.475 0.355 0.473 1.7%

500 Std. Dev. 0.005 0.005 0.005 0.0% Average 0.475 0.355 0.445 25.0%

2,000 Std. Dev. 0.000 0.000 0.006 5.2%

Table 8: Michigan Adhesives FMC 456 -- Compression Set (STM-747)

Exposure Time (hrs)


Thickness (in)




(%)

Average 0.478 0.357 0.351 104.9% 0

Std. Dev. 0.015 0.012 0.010 1.5% Average 0.477 0.357 0.352 103.6%

24 Std. Dev. 0.003 0.003 0.003 0.5% Average 0.479 0.360 0.357 102.8%

168 Std. Dev. 0.010 0.009 0.010 2.0% Average 0.503 0.377 0.376 100.3%

500 Std. Dev. 0.026 0.020 0.020 1.6% Average 0.495 0.373 0.396 81.7%

2,000 Std. Dev. 0.009 0.006 0.013 5.9%

Table 9: Wacker RT 624 -- Compression Set (STM-747)

Exposure Time (hrs)


Thickness (in)




(%)

Average 0.490 0.365 0.493 0.0% 0

Std. Dec. 0.000 0.000 0.005 0.0% Average 0.495 0.370 0.492 2.6%

24 Std. Dec. 0.018 0.013 0.014 4.4% Average 0.500 0.375 0.500 0.0%

168 Std. Dec. 0.000 0.000 0.000 0.0% Average 0.475 0.355 0.475 0.0%

500 Std. Dec. 0.005 0.005 0.005 0.0% Average 0.476 0.355 0.455 17.3%

2,000 Std. Dec. 0.002 0.000 0.006 5.6%

9.1.6.3 Dimension and Weight Change Data Tables

Table 10: Average % Weight Change with Exposure Time Exposure Time (hrs)

Sample Material 0 24 168 500 2,000

Loctite 5714 (Silicone) 0.00% 0.75% 0.34% 0.23% 2.58%

Wacker RT 624 (Silicone) 0.00% 0.11% -0.13% -0.24% -1.45%

Dana (EPDM) 0.00% 0.17% 0.19% 0.14% 0.07%

Michigan Adhesives FCM 456 (PU) 0.00% 7.74% 5.20% 6.44% 6.75%

Table11: Sample Dimensional and Weight Change after 24 Hours Exposure

Sample Replicate Dimensions [mm]

Before Dimensions [mm]

After

Dimensions [mm]

Difference

Weight Before [grams]

Weight After

[grams]

Weight Difference

[grams]

1 149.35 x 149.35 x 1.78 149.35 x 149.35 x 1.78 49.00 49.10 0.10

2 149.35 x 149.35 x 1.78 149.35 x 149.35 x 1.78 48.63 49.10 0.47 Loctite 5714

3 149.35 x 149.61 x 2.03 149.35 x 149.61 x 2.03 47.90 48.41 0.51

1 148.84 x 148.84 x 1.78 148.84 x 148.84 x 1.78 45.46 45.50 0.04

2 149.10 x 149.10 x 1.78 149.10 x 149.10 x 1.78 49.20 49.25 0.05 Wacker RT 624

3 147.83 x 147.83 x 1.78 147.83 x 147.83 x 1.78 49.83 49.90 0.07

1 147.32 x 147.32 x 3.05 147.32 x 147.32 x 3.05 63.58 63.68 0.10

2 147.32 x 147.32 x 2.54 147.32 x 147.32 x 2.54 65.61 65.71 0.10 Dana EPDM

3 147.32 x 147.32 x 2.79 147.32 x 147.32 x 2.79 65.95 66.08 0.13

1 175.51 x 152.65 x 2.03 175.51 x 152.65 x 2.03 97.72 104.67 6.95 FCM 456

2 175.77 x 152.15 x 2.03 175.77 x 152.15 x 2.03

No Difference After

Conditioning

91.21 98.84 7.63

Table 12: Sample Dimensional and Weight Change after 168 Hours Exposure



After

Dimensions [mm]

Difference


Weight After

[grams]

Weight Difference

[grams]

1 149.01 x 149.35 x 2.03 149.01 x 149.35 x 2.03 48.06 48.17 0.11

2 149.35 x 149.35 x 2.03 149.35 x 149.35 x 2.03 47.98 48.18 0.20 Loctite 5714

3 149.35 x 149.35 x 2.03 149.35 x 149.35 x 2.03 48.94 49.12 0.18

1 149.86 x 148.59 x 2.03 149.86 x 148.59 x 2.03 50.32 50.26 -0.06

2 150.88 x 149.35 x 2.03 150.88 x 149.35 x 2.03 50.36 50.33 -0.03 Wacker RT 624

3 149.35 x 149.61 x 2.03 149.35 x 149.61 x 2.03 53.63 53.51 -0.12

1 147.57 x 147.83 x 2.79 147.57 x 147.83 x 2.79 67.60 67.71 0.11

2 147.57 x 147.57 x 3.05 147.57 x 147.57 x 3.05 71.18 71.31 0.13 Dana EPDM

3 147.57 x 147.32 x 3.05 147.57 x 147.32 x 3.05

No Difference

71.15 71.30 0.15

1 185.93 x 152.91 x 2.54 189.99 x 156.21 x 2.29 4.06 x 3.30 x -0.25 100.67 105.95 5.28 FCM 456

2 180.85 x 152.65 x 2.03 185.67 x 157.99 x 1.78 4.82 x 5.34 x -0.25 90.12 94.76 4.64

Table 13: Sample Dimensional and Weight Change after 500 Hours Exposure



After Dimensions [mm]

Difference


Weight After

[grams]

Weight Difference

[grams]

1 149.35 x 150.39 x 2.03 149.35 x 150.39 x 2.03 49.09 49.22 0.13

2 149.61 x 149.61 x 203 149.61 x 149.61 x 203 50.10 50.22 0.12 Loctite 5714

3 149.35 x 149.35 x 2.03 149.35 x 149.35 x 2.03

No Difference

48.54 48.63 0.09

1 149.35 x 149.35 x 2.03 149.10 x 149.10 x 2.03 -0.25 x -0.25 x 0.00 47.14 47.02 -0.12

2 148.59 x 148.84 x 2.03 148.59 x 148.59 x 2.03 0.00 x -0.25 x 0.00 49.47 49.36 -0.11 Wacker RT 624

3 150.37 x 150.37 x 2.03 150.11 x 150.37 x 2.03 -0.26 x 0.00 x 0.00 48.09 47.98 -0.11

1 147.57 x 147.57 x 3.05 147.57 x 147.57 x 3.05 68.76 68.88 0.12

2 148.34 x 148.34 x 3.05 148.34 x 148.34 x 3.05 72.19 72.31 0.12 Dana EPDM

3 147.57 x 148.08 x 2.54 147.57 x 148.08 x 2.54

No Difference

64.39 64.44 0.05

1 180.34 x 154.18 x 2.03 185.67 x 159.51 x 1.52 5.33 x 5.33 x -0.51 91.57 97.68 6.11 FCM 456

2 176.28 x 151.64 x 2.03 183.39 x 158.24 x 1.52 7.11 x 6.60 x -0.51 98.23 104.32 6.09

Table 14: Sample Dimensional and Weight Change after 2,000 Hours Exposure



After Dimensions [mm]

Difference


Weight After

[grams]

Weight Difference

[grams]

1 149.23 x 149.53 x 1.97 149.86 x 150.88 x 2.03 0.51 x 0.51 x 0.00 48.41 49.52 1.11

2 149.25 x 149.59 x 1.95 149.61 x 149.86 x 2.29 0.25 x 0.25 x 0.25 49.44 51.64 2.20 Loctite 5714

3 149.29 x 149.63 x 2.02 149.86 x 150.11 x 2.03 0.51 x 0.51 x 0.00 49.10 49.59 0.49

1 148.96 x 148.96 x 1.86 148.34 x 148.59 x 1.78 -0.51 x -0.25 x 0.00 45.16 44.47 -0.69

2 149.03 x 149.03 x 1.88 148.34 x 148.84 x 1.52 -0.51 x 0.00 x -0.25 48.27 47.54 -0.73 Wacker RT 624

3 147.83 x 147.83 x 1.89 147.57 x 147.57 x 1.78 -0.25 x -0.25 x -0.25 46.39 45.78 -0.61

1 147.42 x 147.42 x 3.12 147.32 x 147.32 x 3.05 72.50 72.53 0.03

2 147.45 x 147.42 x 2.53 147.32 x 147.32 x 3.05 66.19 66.23 0.04 Dana EPDM

3 147.49 x 147.49 x 2.85 147.32 x 147.57 x 2.79

No Difference

70.63 70.71 0.08

1 180.34 x 152.65 x 2.03 182.88 x 158.24 x 2.03 2.54 x 5.59 x 0.00 97.74 103.84 6.10 FCM 456

2 176.28 x 152.40 x 2.29 179.83 x 155.96 x 2.54 3.56 x 3.56 x 0.25 95.89 102.85 6.96

9.1.7 Physical Property Test Observations (After 2,000 hours Exposure)

9.1.7.1 Tensile Strength, Strain, Modulus

The samples tested have a broad diversity in original tensile property values, and the actual values should be considered when comparing “change data” for 2,000 hours exposure. All samples experienced tensile strength loss, with Wacker RT 624 having the least reduction. All samples experienced modulus reduction, with the Wacker RT624 and Dana EPDM having the least change. The Loctite® 5714 sample had a 25% increase in elongation to break, while the other samples had reductions in this value.

9.1.7.2 Shore A Hardness

The Dana EPDM and Wacker RT 624 experienced small changes in hardness; while both the Loctite® 5714 and Michigan Adhesives FCM 456 had a 50% reduction in hardness values.

9.1.7.3 Compression Set

The Michigan Adhesives FCM 456 had the highest compression set (105%) starting at 168 hours of exposure, but after 2,000 hours exposure, the compression set decreased to 82%. The Dana EPDM had the least compression set over the entire exposure period, less than 4%. Both Loctite® 5714 and Wacker RT 624 had near zero change until 2,000 hours exposure, when the compression set jumped to 25% and 17% respectively.

9.1.7.4 Weight

The Dana EPDM sample had the least weight change, showing less than 0.12%. The Michigan Adhesives FCM 456 had the highest weight gain (6.75%); and based on the swelling (greatest volume change), this material was likely degraded and the weight gain possibly due to hydrophilic tendencies resulting from the water exposure. The two silicone samples (Loctite® 5714 and Wacker RT 624) had less than 3.0% increase/decrease respectively, mirroring the area dimensional change response.

9.1.7.5 Dimension

The Michigan Adhesives FCM 456 had the greatest area change, 4.76% increase in the “X-Y” area dimension. The other samples (Dana EPDM, Loctite® 5714 and Wacker RT 624) had less than 0.82% area change. The Wacker RT 624 had the greatest thickness loss of 9.77%, while the other samples all increased in thickness, from 4.59 to 6.90%. The volume change (representing the sum of the area and thickness changes) was greatest for Michigan Adhesives FMC 456 at 10.7% increase; while, Wacker RT 624 lost the most volume at 10.33% reduction.

9.1.7.6 Other Considerations

As an “evaluation exercise” of the test methods, the Gasket Focus Group selected and tested four candidate materials with physical and material properties believed important for sealing the interface of the MEA and individual cells of a PEMFC stack. Thus, this report is not recommending a gasket material, but demonstrating how a candidate material might be evaluated and selected. As mentioned above, each material’s physical properties should be evaluated on both the actual starting values plus the change with exposure time; since the “change with time” may not be as important as the “absolute property value” at the end of the exposure time period.

9.1.7.7 Summary of “Percent Change from Original Values” after 2,000 hours Exposure

Property Dana EPDM Loctite® 5714 FCM 456 Elastosil® RT 624

Tensile - 28.1% - 25.8% - 61.1% - 12.1%

Elongation - 14.4% + 25.0% - 4.57% - 15.3%

Modulus - 28.7% - 57.0% - 68.8% - 6.21%

Hardness - 1.43% - 50.0% - 48.1% + 5.13%

Compression Set + 2.01% + 24.7% - 23.2% + 17.3%

Weight Change + 0.07% + 2.58% + 6.75% - 1.45%

Area Change - 0.12% + 0.82% + 4.76% - 0.54%

Thickness Change + 4.59% + 6.90% + 5.79% - 9.77%

Volume Change + 4.46% + 7.76% + 10.7% - 10.3%

9.2 Fourier Transform Infrared Spectroscopy – Attenuated Total Reflectance

Analysts: R. Herrera and S. Reyes Cerium Labs, LLC 5204 E. Ben White Blvd., MS 512 Austin, TX 78741 1.866.770.7752

9.2.1 Equipment:

FTIR: Thermo Nicolet 4700

4000 to 600 cm-1 scan range 128 scans 4 cm-1 resolution DTGS detector CsI beam splitter Happ-Genzel apodization Mertz phase correction N2 purged

ATR: Graseby Specac Golden Gate

Type IIa diamond, 2 mm x 2 mm 0.6 mm focused aperture 45° single reflection 1.6 micron penetration depth KRS5 lenses (250 cm-1 cut off) N2 purged

ATR: Harrick GATR

Germanium crystal 65° single reflection 0.6 micron penetration depth N2 purged

9.2.2 Test Method

1. Rinse specimen with ultrapure water to remove any loose surface debris & air dry at room temperature inside a laminar flow hood.

2. Clean the ATR crystal with semiconductor grade IPA, and wipe dry with a clean tissue wiper.

3. Collect a background absorption spectrum of the clean crystal over the range 4000-600 cm-1.

4. Place a representative area of the specimen surface into direct contact with the ATR crystal and apply a force of 40-80 cN·m to the specimen, so that it remains in intimate contact with the crystal.

5. Collect an absorption spectrum of the sample over the range 4000-600 cm-1 and display the spectrum ratioed against the previously collected background spectrum.

6. Perform an advanced ATR spectral correction of the displayed spectrum to compensate for the variation of penetration depth with wave number.

7. Identify characteristic functional groups corresponding to principal absorptions in the spectrum.

8. Compare changes in functional groups with respect to temperature, time, solvent or similar variables.

9. Correlate changes in functional groups with possible reaction or degradation mechanisms.

10. Provide a summary report of findings, with the absorbance values for characteristic functional groups presented in the charts that follow this section.

9.2.3 Sample Sets

Test Facility Sample Hours Wacker Wacker Elastosil® RT 624 0Wacker Wacker Elastosil® RT 624 24Wacker Wacker Elastosil® RT 624 168Wacker Wacker Elastosil® RT 624 500Wacker Wacker Elastosil® RT 624 2,000Wacker Dana EPDM 24Wacker Dana EPDM 168Wacker Dana EPDM 500Wacker Dana EPDM 2,000Wacker Henkel Loctite® 5714 24Wacker Henkel Loctite® 5714 168Wacker Henkel Loctite® 5714 500Wacker Henkel Loctite® 5714 2,000Wacker Michigan Adhesive FCM 456 24Wacker Michigan Adhesive FCM 456 168Wacker Michigan Adhesive FCM 456 500Wacker Michigan Adhesive FCM 456 2,000Dana Wacker Elastosil® RT 624 24Dana Wacker Elastosil® RT 624 168Dana Wacker Elastosil® RT 624 525Dana Wacker Elastosil® RT 624 2,000Dana Dana EPDM 24Dana Dana EPDM 168Dana Dana EPDM 525Dana Dana EPDM 2,000Dana Henkel Loctite® 5714 24Dana Henkel Loctite® 5714 168Dana Henkel Loctite® 5714 525Dana Henkel Loctite® 5714 2,000Dana Michigan Adhesive FCM 456 24Dana Michigan Adhesive FCM 456 168Dana Michigan Adhesive FCM 456 525Dana Michigan Adhesive FCM 456 2,000Henkel Wacker Elastosil® RT 624 0Henkel Wacker Elastosil® RT 624 24Henkel Wacker Elastosil® RT 624 168Henkel Wacker Elastosil® RT 624 500Henkel Wacker Elastosil® RT 624 2,000Henkel Dana EPDM 0Henkel Dana EPDM 24Henkel Dana EPDM 168Henkel Dana EPDM 500

Test Facility Sample Hours Henkel Dana EPDM 2,000Henkel Henkel Loctite® 5714 0Henkel Henkel Loctite® 5714 24Henkel Henkel Loctite® 5714 168Henkel Henkel Loctite® 5714 500Henkel Henkel Loctite® 5714 2,000Henkel Michigan Adhesive FCM 456 0Henkel Michigan Adhesive FCM 456 24Henkel Michigan Adhesive FCM 456 168Henkel Michigan Adhesive FCM 456 500Henkel Michigan Adhesive FCM 456 2,000

9.2.4 ATR-FTIR Test Observations

9.2.4.1 Michigan Adhesives FCM 456

Material is polyether urethane containing “substantial” calcium carbonate filler.

Carbonate distribution at the sample surface is variable.

The 168, 500, 2,000 hour samples from Wacker showed greater water content than corresponding samples from the other two test sites.

9.2.4.2 Wacker Elastosil® RT 624

Material is unfilled silicone (polydimethylsiloxane).

The 168 hour sample from Wacker and the 500 hour sample from Henkel Loctite® showed trace oxidation.

9.2.4.3 Dana EPDM

The material is carbon filled ethylene-propylene-diene polymer.

Two absorptions were found in the samples from Wacker and Henkel Loctite® that were not seen in the Control or the samples from Dana. The absorption @ 1576 cm-1 indicates an ionized carboxylate CH2-COO salt of a carboxylic acid (like zinc stearate). The absorption at 1540 cm-1 suggests carbon-nitrogen bonding in general, such as found in C-NO2 (nitro) and C-NH3 (amine hydrochloride).

The 500 and 2,000 hour samples from Wacker and the 500 and 2,000 hour samples from Dana produced a weak intensity spectrum as seen from the absorbance scale (y-axis). This was due to increased surface roughness (see photos).

Traces of silicone were also found in all EPDM samples.

Slight hydration was found in the Henkel Loctite® 500 and 2,000 hour samples.

9.2.4.4 Henkel Loctite® 5714

Material is unfilled silicone (polydimethylsiloxane).

No significant differences in exposed samples compared to the control other than overall intensity values.

The peaks found in the Wacker and Loctite® samples at absorptions of 1576 cm-1and 1540 cm-1 were also seen in the Loctite® 2,000 hour sample.

The Wacker and Loctite® 2,000 hour sample is showing more surface roughness than the Dana sample as demonstrated by lower Si-O-Si values.

19 19 28 October 2009

ATR-FTIR: Observations

Wacker EPDM 500 hour sample surface is dull and pitted.

The 2000 hour sample from Wacker and the 500 and 2000 hour samples from Dana also showed a rough surface.

Henkel EPDM 0 hour sample surface is smooth shinny black with no pits.

This type of surface was also seen on the 24 hour and 168 hour samples from the three test sites.

1 1 28 October 2009

ATR-FTIR: Michigan Adhesives FCM-456 24 Hour Data

FCM-456 Hours

Hydroxyl(-OH)

@3415cm-1

Hydrocarbon(-CH)

@2970cm-1

Carbonyl(-C=O)

@1730cm-1

Water(H-O-H)

@1635cm-1

Carbonate(CO3)

@1444cm-1

EtherC-O-C

@1109cm-1

CO3/C-O-Cratio

(-CH)/C-O-Cratio

(H-O-H)/(-OH)ratio

Test Facility: Control - 0 0.015 0.136 0.003 0.003 0.857 0.233 3.678 0.584 0.200

Dana 24 0.019 0.137 0.004 0.004 0.801 0.246 3.256 0.557 0.211

Henkel 24 0.015 0.140 0.002 0.002 0.860 0.239 3.598 0.586 0.133

Average= 0.016 0.140 0.003 0.003 0.857 0.237 3.623 0.591 0.153

Std deviation= 0.003 0.003 0.001 0.001 0.055 0.010 0.379 0.037 0.051

Wacker 24 0.014 0.143 0.003 0.002 0.911 0.227 4.013 0.630 0.114

Control - Michigan Adhesive FCM-456 0hrs- ATR2 0.8

0.6

0.2

Abs 0.4

Dana - Michigan Adhesive FCM-456 24hrs- ATR2

0.2

0.4

0.6

0.8

Abs

Wacker - Michigan Adhesive FCM-456 24hrs- ATR2 0.8

0.2

0.4

0.6Abs

Henkel - Michigan Adhesive FCM-456 24hrs- ATR2

0.2

0.4

0.6

0.8

Abs

1000 1500 2000 2500 3000 3500 4000 Wavenumbers (cm-1)

10 10 28 October 2009


FCM-456 Hours

Hydroxyl(-OH)

@3415cm-1

Hydrocarbon(-CH)

@2970cm-1

Carbonyl(-C=O)

@1730cm-1

Water(H-O-H)

@1635cm-1

Carbonate(CO3)

@1444cm-1

EtherC-O-C

@1109cm-1

CO3/C-O-Cratio

(-CH)/C-O-Cratio

(H-O-H)/(-OH)ratio


Dana 168 0.016 0.135 0.006 0.002 0.942 0.215 4.381 0.628 0.119

Henkel 168 0.016 0.141 0.003 0.002 0.863 0.240 3.596 0.588 0.125

Average= 0.031 0.133 0.003 0.004 0.872 0.217 4.037 0.614 0.125

Std deviation= 0.027 0.009 0.003 0.004 0.066 0.022 0.401 0.023 0.007

Wacker 168 0.062 0.123 0.001 0.008 0.810 0.196 4.133 0.628 0.132

Control - Michigan Adhesive FCM-456 0hrs- ATR2

1.0

Abs 0.5

0.0Dana -Michigan Adhesive FCM-456 168hrs- ATR2

1.0Abs

0.5

0.0Wacker - Michigan Adhesive FCM-456 168hrs- ATR2

1.0

Abs 0.5

0.0Henkel - Michigan Adhesive FCM-456 168hrs- ATR2

1.0Abs

0.5

0.0

1000 1500 2000 2500 3000 3500 4000 Wavenumbers (cm-1)

11 11 28 October 2009


FCM-456 Hours

Hydroxyl(-OH)

@3415cm-1

Hydrocarbon(-CH)

@2970cm-1

Carbonyl(-C=O)

@1730cm-1

Water(H-O-H)

@1635cm-1

Carbonate(CO3)

@1444cm-1

EtherC-O-C

@1109cm-1

CO3/C-O-Cratio

(-CH)/C-O-Cratio

(H-O-H)/(-OH)ratio


Dana 525 0.020 0.133 0.003 0.003 0.882 0.233 3.785 0.571 0.150

Henkel 500 0.018 0.143 0.002 0.003 0.883 0.239 3.695 0.598 0.167

Average= 0.032 0.132 0.002 0.004 0.853 0.225 3.799 0.588 0.145

Std deviation= 0.023 0.011 0.001 0.002 0.051 0.019 0.111 0.015 0.024

Wacker 500 0.059 0.121 0.001 0.007 0.795 0.203 3.916 0.596 0.119

Control - Michigan Adhesive FCM-456 0hrs - ATR2

0.2

0.4

0.6

0.8

Abs

Dana - Michigan Adhesive FCM-456 525hrs - ATR2

0.2

0.4

0.6

0.8

Abs

Wacker - Michigan Adhesive FCM-456 500hrs - ATR2

0.2

0.4

0.6

0.8

Abs

Henkel - Michigan Adhesive FCM-456 500hrs - ATR2

0.2

0.4

0.6

0.8

Abs

1000 1500 2000 2500 3000 3500 4000 Wavenumbers (cm-1)

12 12 28 October 2009


FCM-456 Hours

Hydroxyl(-OH)

@3415cm-1

Hydrocarbon(-CH)

@2970cm-1

Carbonyl(-C=O)

@1730cm-1

Water(H-O-H)

@1635cm-1

Carbonate(CO3)

@1444cm-1

EtherC-O-C

@1109cm-1

CO3/C-O-Cratio

(-CH)/C-O-Cratio

(H-O-H)/(-OH)ratio


Dana 2000 0.063 0.121 0.002 0.009 0.852 0.199 4.281 0.608 0.143

Henkel 2000 0.024 0.147 0.003 0.004 0.968 0.247 3.919 0.595 0.167

Average= 0.052 0.130 0.002 0.008 0.881 0.216 4.097 0.603 0.152

Std deviation= 0.024 0.015 0.001 0.003 0.077 0.027 0.181 0.007 0.013

Wacker 2000 0.068 0.122 0.001 0.010 0.822 0.201 4.090 0.607 0.147

Controll - Michigan Adhesive FCM-456 0hrs - ATR2 1.0

Abs 0.5

Dana - Michigan Adhesive FCM-456 2000hrs - ATR2 1.0

Abs 0.5

Wacker - Michigan Adhesive FCM-546 2000hrs - ATR2 1.0

Abs 0.5

Henkel - Michigan Adhesive FCM-456 2000hrs - ATR2 1.0

Abs 0.5

1000 1500 2000 2500 3000 3500 Wavenumbers (cm-1)

13 13 28 October 2009

ATR-FTIR: Wacker Elastosil TR624 24 Hour Data

No Wacker 24 hour sample from Henkel

Elastosil RT624 Hours

Hydroxyl(-OH)

@ 3379cm-1

Hydrocarbon(-CH)

@ 2962cm-1

Carbonyl(-C=O)

@ 1726cm-1

Water(H-O-H)

@ 1630cm-1

Si-CH3

@ 1259cm-1

Si-O-Si

@ 1086cm-1

Si-O-Si

@ 1016cm-1

Si-CH3

@ 800cm-1

Test Facility: Control - 0 0.001 0.164 0.000 0.002 0.438 0.632 0.494 0.546

Dana 24 0.001 0.163 0.000 0.001 0.437 0.633 0.492 0.543

Henkel 24 no sample no sample no sample no sample no sample no sample no sample no sample

Average= 0.001 0.164 0.001 0.002 0.439 0.635 0.493 0.546

Std Deviation= 0.001 0.001 0.001 0.001 0.002 0.003 0.001 0.004

Wacker 24 0.000 0.164 0.001 0.002 0.440 0.637 0.493 0.548

Control - Wacker RT624 0hrs- ATR2 0.6

0.4Abs

0.2

-0.0Dana - Wacker RT624 24hrs- ATR2 0.6

0.4Abs

0.2

-0.0Wacker - Wacker RT624 24hrs- ATR2 0.6

0.4A

0.2

-0.0

bs

Henkel - Wacker RT624 24hrs ATR2

50

100

%T

1000 1500 2000 2500 3000 3500 4000 Wavenumbers (cm-1)

14 14 28 October 2009



Hydroxyl(-OH)

@ 3379cm-1

Hydrocarbon(-CH)

@ 2962cm-1

Carbonyl(-C=O)

@ 1726cm-1

Water(H-O-H)

@ 1630cm-1

Si-CH3

@ 1259cm-1

Si-O-Si

@ 1086cm-1

Si-O-Si

@ 1016cm-1

Si-CH3

@ 800cm-1


Dana 168 0.001 0.163 0.000 0.001 0.437 0.632 0.494 0.547

Henkel 168 0.001 0.164 0.001 0.002 0.442 0.641 0.503 0.553

Average= 0.001 0.163 0.002 0.002 0.439 0.634 0.497 0.550

Std Deviation= 0.000 0.001 0.002 0.001 0.003 0.006 0.005 0.003

Wacker 168 0.001 0.163 0.004 0.002 0.439 0.630 0.494 0.550

Control - Wacker RT624 0hrs- ATR2 0.6

0.4Abs

0.2

-0.0Dana - Wacker RT624 168hrs- ATR2 0.6

0.4Abs

0.2

Wacker - Wacker RT 624 168hrs- ATR2 0.6

0.4Abs

0.2

-0.0Henkel - Wacker RT624 168hrs- ATR2

0.0

0.2

0.4

0.6

Abs

1000 1500 2000 2500 3000 3500 4000 Wavenumbers (cm-1)

15 15 28 October 2009



Hydroxyl(-OH)

@ 3379cm-1

Hydrocarbon(-CH)

@ 2962cm-1

Carbonyl(-C=O)

@ 1726cm-1

Water(H-O-H)

@ 1630cm-1

Si-CH3

@ 1259cm-1

Si-O-Si

@ 1086cm-1

Si-O-Si

@ 1016cm-1

Si-CH3

@ 800cm-1


Dana 525 0.002 0.163 0.001 0.002 0.436 0.634 0.491 0.541

Henkel 500 0.002 0.164 0.003 0.002 0.439 0.632 0.501 0.543

Average= 0.002 0.164 0.001 0.002 0.438 0.632 0.504 0.546

Std Deviation= 0.001 0.001 0.002 0.000 0.002 0.003 0.015 0.006

Wacker 500 0.001 0.165 0.000 0.002 0.440 0.629 0.520 0.553

Control - Wacker RT624 0hrs - ATR2 0.6

0.4Abs

0.2

-0.0Dana - Wacker RT624 525hrs - ATR2 0.6

0.4Abs

0.2

0.0Wacker - Wacker RT624 500 hrs - ATR2 0.6

0.4Abs

0.2

0.0Henkel - Wacker RT624 500hrs - ATR2 0.6

0.4Abs

0.2

-0.01000 1500 2000 2500 3000 3500 4000

Wavenumbers (cm-1)

16 16 28 October 2009



Hydroxyl(-OH)

@ 3379cm-1

Hydrocarbon(-CH)

@ 2962cm-1

Carbonyl(-C=O)

@ 1726cm-1

Water(H-O-H)

@ 1630cm-1

Si-CH3

@ 1259cm-1

Si-O-Si

@ 1086cm-1

Si-O-Si

@ 1016cm-1

Si-CH3

@ 800cm-1


Dana 2000 0.001 0.165 0.000 0.003 0.442 0.635 0.509 0.551

Henkel 2000 0.001 0.164 0.000 0.003 0.444 0.642 0.513 0.555

Average= 0.001 0.165 0.000 0.003 0.443 0.636 0.515 0.555

Std Deviation= 0.000 0.001 0.000 0.000 0.001 0.006 0.008 0.004

Wacker 2000 0.001 0.166 0.000 0.003 0.443 0.631 0.524 0.559

Control - Wacker RT624 0hr ATR2) 0.6

0.4Abs

0.2

-0.0Dana - Wacker RT624 2000hrs ATR2 0.6

0.4Abs

0.2

Wacker - Wacker RT624 2000hrs ATR2 0.6

-0.0

0.2

0.4Abs

Henkel - Wacker RT624 2000hrs ATR2 0.6

0.4Abs

0.2

-0.01000 1500 2000 2500 3000 3500 4000

Wavenumbers (cm-1)

17 17 28 October 2009

ATR-FTIR: Dana EPDM 24 Hour Data

EPDM Hours

Hydroxyl(-OH)

@ 3359cm-1

Hydrocarbon(-CH)

@ 2912cm-1

Carbonyl(-C=O)

@ 1732cm-1

Water(H-O-H)

@ 1620cm-1

UnknownPeak

@ 1576cm-1

UnknownPeak

@ 1540cm-1

CH2deformation

@ 1464cm-1

Test Facility: Control - 0 0.011 0.402 0.001 0.000 0.002 0.001 0.063

Dana 24 0.015 0.401 0.005 0.000 0.000 0.000 0.079

Henkel 24 0.020 0.568 0.005 0.008 0.170 0.194 0.114

Average= 0.015 0.459 0.004 0.003 0.059 0.078 0.088

Std deviation= 0.005 0.095 0.001 0.005 0.096 0.102 0.023

Wacker 24 0.010 0.407 0.003 0.000 0.006 0.041 0.072

Control - Dana EPDM 0hrs - GATR

0.6

Abs 0.4

0.2

Dana - Dana EPDM 24hrs - GATR

0.6

0.2

Abs 0.4

Wacker - Dana EPDM 24hrs - GATR

0.6

0.2

Abs 0.4

Henkel - Dana EPDM 24hrs - GATR

0.6

Abs 0.4

0.2

1000 1500 2000 2500 3000 3500 Wavenumbers (cm-1)

18 18 28 October 2009


EPDM Hours

Hydroxyl(-OH)

@ 3359cm-1

Hydrocarbon(-CH)

@ 2912cm-1

Carbonyl(-C=O)

@ 1732cm-1

Water(H-O-H)

@ 1620cm-1

UnknownPeak

@ 1576cm-1

UnknownPeak

@ 1540cm-1

CH2deformation

@ 1464cm-1


Dana 168 0.021 0.390 0.003 0.000 0.000 0.000 0.069

Henkel 168 0.028 0.497 0.004 0.007 0.154 0.180 0.105

Average= 0.019 0.429 0.003 0.002 0.052 0.061 0.080

Std deviation= 0.010 0.059 0.001 0.004 0.088 0.103 0.022

Wacker 168 0.008 0.401 0.003 0.000 0.002 0.004 0.066

Control - Dana EPDM 0hrs - GATR

0.6

Abs 0.4

0.2


0.6

Abs 0.4

0.2

Wacker - Dana EPDM 168hrs - GATR

0.2

0.4

0.6

Abs

Henkel - Dana EPDM 168hrs - GATR

0.6

Abs 0.4

0.2

1000 1500 2000 2500 3000 3500 4000 Wavenumbers (cm-1)

19 19 28 October 2009


Small change in control values due to spectra baseline

EPDM Hours

Hydroxyl(-OH)

@ 3375cm-1

Hydrocarbon(-CH)

@ 2912cm-1

Carbonyl(-C=O)

@ 1710cm-1

Water(H-O-H)

@ 1643cm-1

UnknownPeak

@ 1576cm-1

UnknownPeak

@ 1540cm-1

CH2deformation

@ 1464cm-1


Dana 525 0.009 0.021 0.009 0.000 0.016

Henkel 500 0.045 0.244 0.004 0.036 0.073 0.081 0.053

Average= 0.021 0.098 0.007 0.012 0.032 0.027

Std deviation= 0.021 0.127 0.003 0.021 0.036 0.022

0.010 @ 1576cm-1

Wacker 500 0.008 0.028 0.008 0.000 0.0130.012 @ 1576cm-1

Henkel - Dana EPDM 0 hrs - GATR 0.4

Abs 0.2

0.0Dana - Dana EPDM 525hrs - GATR 0.4

Abs 0.2

0.0Wacker - Dana EPDM 500 hrs - GATR 0.4

Abs 0.2

0.0Henkel - Dana EPDM 500hrs - GATR) 0.4

Abs 0.2

0.01000 1500 2000 2500 3000 3500 4000

Wavenumbers (cm-1)

20 20 28 October 2009


Small change in control values due to spectra baseline

EPDM Hours

Hydroxyl(-OH)

@ 3375cm-1

Hydrocarbon(-CH)

@ 2912cm-1

Carbonyl(-C=O)

@ 1710cm-1

Water(H-O-H)

@ 1643cm-1

UnknownPeak

@ 1576cm-1

UnknownPeak

@ 1540cm-1

CH2deformation

@ 1464cm-1


Dana 2000 0.002 0.013 0.006 0.000 0.008

Henkel 2000 0.037 0.366 0.004 0.006 0.090 0.096 0.076

Average= 0.015 0.130 0.005 0.002 0.035 0.031

Std deviation= 0.019 0.204 0.001 0.003 0.047 0.039

0.008 @ 1570cm-1

Wacker 2000 0.006 0.012 0.006 0.000 0.0080.008 @ 1570cm-1

Control - Dana EPDM 0 hrs - GATR

-0.0

0.1

0.2

0.4

0.3Abs


0.0

0.1

0.2

0.4

0.3

Abs

Wacher - Dana EPDM 2000hrs - GATR 0.4

0.0

0.1

0.2

0.3

Abs

Henkel - Dana EPDM 2000hrs - GATR) 0.4

0.0

0.1

0.2

0.3Abs

1000 1500 2000 2500 3000 3500 4000 Wavenumbers (cm-1)

21 21 28 October 2009

ATR-FTIR: Henkel Loctite 24 Hour Data

Loctite 5714 Hours

Hydroxyl(-OH)

@ 3377cm-1

Hydrocarbon(-CH)

@ 2962cm-1

Carbonyl(-C=O)

@ 1730cm-1

Water(H-O-H)

@ 1620cm-1

Si-CH3

@ 1259cm-1

Si-O-Si

@ 1091cm-1

Si-O-Si

@ 1016cm-1

Si-CH3

@ 800cm-1


Dana 24 0.002 0.176 0.000 0.003 0.492 0.528 0.546 0.635

Henkel 24 0.002 0.174 0.000 0.004 0.488 0.531 0.544 0.628

Average= 0.002 0.175 0.000 0.003 0.492 0.532 0.544 0.633

Std deviation= 0.000 0.001 0.000 0.001 0.004 0.005 0.002 0.005

Wacker 24 0.002 0.174 0.000 0.003 0.496 0.537 0.542 0.637

Control - Henkel Loctite 5714 0hrs- ATR2 0.6

0.4Abs

0.2

-0.0Dana - Henkel Loctite 5714 24hrs- ATR2 0.6

0.4Abs

0.2

0.0Wacker - Henkel Loctite 5714 24hrs- ATR2 0.6

0.4Abs

0.2

Henkel - Henkel Loctite 5714 24hrs- ATR2 0.6

0.4Abs

0.2

-0.01000 1500 2000 2500 3000 3500 4000

Wavenumbers (cm-1)

22 22 28 October 2009


Loctite 5714 Hours

Hydroxyl(-OH)

@ 3377cm-1

Hydrocarbon(-CH)

@ 2962cm-1

Carbonyl(-C=O)

@ 1730cm-1

Water(H-O-H)

@ 1620cm-1

Si-CH3

@ 1259cm-1

Si-O-Si

@ 1091cm-1

Si-O-Si

@ 1016cm-1

Si-CH3

@ 800cm-1


Dana 168 0.002 0.174 0.000 0.003 0.495 0.537 0.553 0.639

Henkel 168 0.003 0.172 0.000 0.004 0.505 0.543 0.526 0.584

Average= 0.002 0.174 0.000 0.003 0.499 0.540 0.543 0.622

Std deviation= 0.001 0.002 0.000 0.001 0.005 0.003 0.015 0.033

Wacker 168 0.002 0.175 0.000 0.003 0.498 0.540 0.549 0.642

Control - Henkel Loctite 5714 0hrs - ATR2 0.6

0.4Abs

0.2

-0.0Dana - Henkel Loctite 5714 168hrs - ATR2 0.6

0.4Abs

0.2

-0.0Wacker - Henkel Loctite 5714 168hrs - ATR2 0.6

0.4Abs

0.2

0.0Henkel - Henkel Loctite 5714 168hrs - ATR2 0.6

0.4Abs

0.2

1000 1500 2000 2500 3000 3500 4000 Wavenumbers (cm-1)

23 23 28 October 2009


Loctite 5714 Hours

Hydroxyl(-OH)

@ 3377cm-1

Hydrocarbon(-CH)

@ 2962cm-1

Carbonyl(-C=O)

@ 1730cm-1

Water(H-O-H)

@ 1620cm-1

Si-CH3

@ 1259cm-1

Si-O-Si

@ 1091cm-1

Si-O-Si

@ 1016cm-1

Si-CH3

@ 800cm-1


Dana 525 0.004 0.172 0.000 0.003 0.488 0.538 0.545 0.626

Henkel 500 0.004 0.172 0.000 0.004 0.486 0.523 0.524 0.578

Average= 0.003 0.173 0.000 0.003 0.490 0.532 0.540 0.615

Std deviation= 0.001 0.001 0.000 0.001 0.005 0.008 0.014 0.033

Wacker 500 0.002 0.174 0.000 0.003 0.495 0.536 0.551 0.640

Control - Henkel Loctite 5714 0hrs - ATR2 0.6

0.4Abs

0.2

Dana - Henkel Loctite 5714 525hrs - ATR2 0.6

0.4Abs

0.2

Wacker - Henkel Loctite 5714 500 hrs - ATR2 0.6

A 0.4bs

0.2

Henkel - Henkel Loctite 5714 500hrs - ATR2 0.6

0.4Abs

0.2

1000 1500 2000 2500 3000 3500 4000 Wavenumbers (cm-1)

24 24 28 October 2009


Loctite 5714 Hours

Hydroxyl(-OH)

@ 3377cm-1

Hydrocarbon(-CH)

@ 2962cm-1

Carbonyl(-C=O)

@ 1730cm-1

Water(H-O-H)

@ 1620cm-1

Si-CH3

@ 1259cm-1

Si-O-Si

@ 1091cm-1

Si-O-Si

@ 1016cm-1

Si-CH3

@ 800cm-1


Dana 2000 0.006 0.170 0.000 0.004 0.489 0.525 0.497 0.530

Henkel 2000 0.005 0.167 0.001 0.003 0.456 0.475 0.443 0.453

Average= 0.005 0.168 0.001 0.003 0.474 0.501 0.467 0.486

Std deviation= 0.002 0.002 0.001 0.001 0.017 0.025 0.027 0.040

Wacker 2000 0.003 0.168 0.001 0.003 0.477 0.503 0.462 0.475

Control - Henkel Loctite 5714 0hrs - ATR2

-0.0

0.2

0.4

0.6

Abs

Dana - Henkel Loctite 5714 2000hrs - ATR2

-0.0

0.2

0.4

0.6

Abs

Wacker - Henkel Loctite 5714 2000hrs - ATR2

-0.0

0.2

0.4

0.6

Abs

Henkel - Henkel Loctite 5714 2000hrs - ATR2

1000 1500 2000 2500 3000 3500 -0.0

4000 Wavenumbers (cm-1)

0.6

0.4

0.2

Abs

10 Bibliography

10.1 Journal Articles and Public Documents

1. Fuel Cells for Power Generation, (2007), US Fuel Cell Council/Fuel Cell and Hydrogen Energy Association.

2. PEM Fuel Cell Durability, M. Sathya and T.J. Jarvi, UTC Power Corporation (2006).

3. Low Cost, Durable Seals For PEM Fuel Cells – J. Parsons, UTC Power Corporation, May 21, 2009 (http://www.hydrogen.energy.gov/pdfs/review09/fc_42_parsons.pdf).

4. Degradation of sealings for PEFC test cells during fuel cell operation, M. Schulze, T. Knöri, A. Schneider, E. Gülzowa, Journal of Power Sources, 127 (2004), pp. 222–229.

5. Description of gasket failure in a 7 cell PEMFC stack, A. Husar, M. Serra, C. Kunusch, Journal of Power Sources, 169 (2007), pp 85-91.

6. Degradation of silicone rubber under compression in a simulated PEM fuel cell environment, J. Tan, Y.J. Chao, X. Li, J.W. Van Zee, Journal of Power Sources, 172 (2) (2007), pp. 782–789.

7. Chemical degradation of five elastomeric seal materials in a simulated and an accelerated PEM fuel cell environment, C-W. Lin, C-H. Chien, J. Tan, Y.J. Chao, J.W. Van Zee, Journal of Power Sources, Volume 196, Issue 4, (2011), pp 1955-1966.

8. Degradation of elastomeric gasket materials in PEM fuel cells, J. Tan, Y.J. Chao, J.W. Van Zee, W.K. Lee, Material Science and Engineering, A 445-446 (2007) pp. 669-675.

9. Gaskets: Important Durability Issues, R. Bieringer, M. Adler, S. Geiss and M. Viol, Polymer Electrolyte Fuel Cell Durability, F.N. Büchi et al. (eds.), Springer Science+Business Media, (2009), pp 271-281, DOI: 10.1007/978-0-387-85536-3, ISBN: 978-0-387-85534-9.

10. Degradation Of Gasket Materials In A Simulated Fuel Cell Environment, J. Tan, Y.J. Chao, W-K. Lee, C.S. Smith, J.W. Van Zee, C.T. Williams, FuelCell2006-97124, ASME Proceedings of FuelCell2006 at the 4th International Conference on Fuel Cell Science, Engineering and Technology (2006).

10.2 Supplier Material Information Data Sheets

1. Dana EPDM (no data sheet available)

2. Henkel Loctite® 5714™ Silicone

3. Michigan Adhesive MG-4150 Polyurethane (used to make “FCM-456”)

4. Wacker Elastosil® RT 624, RTV-2 Silicone Rubber

10.3 Availability of Documents and Standards

Journal, Book and Conference articles from the Journal of Power Sources, Elsevier, Springer Science+Business Media and ASME are available from the respective publisher’s web sites – www.sciencedirect.com, www.elsevier.com/locate/msea, www.springer.com, www.asmedl.org.

The other bibliography documents and the Supplier Material Data Sheets, are available at the Fuel Cell and Hydrogen Energy Association’s web site – www.fchea.org (Fuel Cell Members Section).

The ASTM Standards are available at www.webstore.ansi.org.


http://www.sciencedirect.com/

http://www.elsevier.com/locate/msea

http://www.springer.com/

http://www.asmedl.org/

http://www.fchea.org/

http://www.webstore.ansi.org/

10.4 Supplier and Test Site Information

The following suppliers provided candidate gasket materials for this report:

1. Cerium Labs, LLC 5204 E. Ben White Blvd., MS 512 Austin, TX 78741 Tel. +1 866 770-7752 www.ceriumlabs.com

2. Dana Holding Corporation 100 Plumley Drive Paris, TN 38242 www.dana.com

3. Henkel Corporation One Henkel Way Rocky Hill, CT 06067 Tel. 860-571-5100 Fax 860-571-5358 www.loctite.com

4. Michigan Adhesive Manufacturing, Inc. now operating under “Seal Bond” corporate name:

Seal Bond Attn: Scott Carmichael ([email protected]) 14851 Michael Lane Spring Lake, MI, 49456 Tel. +1 800.252.4144 www.seal-bond.com

5. Wacker Chemical Corporation 3301 Sutton Road Adrian, MI 49221-9397 Tel. +1 888 922-5374 Fax +1 517 264-8246 www.wacker.com alternative address and contact information:

Wacker-Chemie GmbH Wacker-Silicones Hanns-Seidel-Platz 4 D-81737 Munich, Germany Silicone-Info Service Germany: 0-800-6279-800 International: +1 800-6279-8000 www.wacker.com

http://www.ceriumlabs.com/

http://www.dana.com/

http://www.loctite.com/

mailto:[email protected]

http://bing.com/maps/default.aspx?v=2&mid=8100&rtp=%7Eadr.14851+Michael+Lane%2C+Spring+Lake%2C+MI%2C+49456

http://www.seal-bond.com/

http://www.wacker.com/

http://www.wacker.com/

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