Chad A. Ulven, PhD – Associate Professor Mechanical Engineering Department

North Dakota State University (NDSU)

Fargo, ND 58102 USA

The Design of Biocomposite Materials

Biopolymers & Biocomposites Workshop - August 14, 2012 Iowa State University, Ames, IA

Collaborators: D. Webster, L. Jiang, D. Wiesenborn, S. Pryor, B. Chisholm, M. Sibi,

D. Bajwa, S. Huo – North Dakota State University S. McKay, S. Potter, M. Alcock, S. Meatherall – Composites

Innovation Centre (CIC) R. Plagemann, N. Ravindran– Tecton Products

J. Hertsgaard, S. Geiger – SpaceAge Synthetics, Inc. J. Hogue – FlaxStalk, Natural Fiber Solutions

J. Peterson – AGCO Corporation J. Dworshak – Steinwall, Inc.

J. Olson, B. Briggs – John Deere Co. A. Hill – Bobcat Co.

W. Welland, J. Myers - Hyundai-Kia America Technical Center, Inc.

Current NDSU Students: J. Lattimer, B. Nerenz, S. Munusamy, J. Flynn, N. Hosseini, C. Taylor,

R. Whitacre, T. Krosbakken, B. Lisburg, & K. Luick

Biocomposite Development at North Dakota State Univ.

Biocomposite Research Approach at NDSU

Natural Fibers

Vegetable Oil

Liquid Molding Processing

Biobased CompositeMaterials

Plant Breeding & Processing

Vegetable Proteins

Twin Screw Extrusion

Commercial Applications

Natural Fibers

Vegetable Oil

Liquid Molding Processing

Biobased CompositeMaterials

Plant Breeding & Processing

Vegetable Proteins

Twin Screw Extrusion

Commercial Applications

A multidisciplinary team has been assembled focused on improving the growth, harvesting, treatments, and

development of new agri-based precursors for processing structural biocomposites in local and regional composite

manufacturing facilities for use in a wide range of applications

Motivation for Biocomposites Research

Biocomposite materials will emerge as an important engineering material as the technology evolves through

strong collaboration by several facets of the entire production

Farmers & Processors

Plastics & Composite

Manufacturers

Commodity Groups

University & Industry

Researchers

Biocomposite Project Areas

Short Natural Fiber Research Utilization of “waste” cellulose fiber: DDGS, sunflower hull, sugar beet pulp, oat hull, etc.

Long Natural Fiber Research Utilization of residual flax, hemp, grasses, etc.: Aspect Ratios (L/D) >2000

Biopolymer Development Research Utilization of different vegetable oils, proteins, starches, etc. as building blocks for new resins

Biocomposites Investigated To-Date at NDSU

*Fibers: flax, flax shive, hemp,

sugar beet pulp, sunflower hull, DDGS, corn chaff, corn cob,

oat hull, etc. *Polymers:

polypropylene, polyethylene,

acrylonitrile butadiene styrene, polymethyl

methacrylate, polyvinyl chloride, nylon, vinyl

ester, epoxy, polyurethane, etc.

*Fiber volume fractions from 5-50% *Multitude of chemical treatments

Design Approach with Biocomposites

Provide a means for interested companies, research groups, and other faculty to work towards developing polymer matrix

composite solutions for a wide variety of applications

Function Recognition & Specifications

With composites, one must design the material for a specific application

and/or function

Feasibility Study

? Process Design

Prototype Creation & Verification

Material Selection / Part Design

Production Implementation

???

Data Sheet Generation for Biocomposites at NDSU

Biocomposite Project Areas

Short Natural Fiber Research Utilization of “waste” cellulose fiber: DDGS, sunflower hull, sugar beet pulp, oat hull, etc.

Long Natural Fiber Research Utilization of residual flax, hemp, grasses, etc.: Aspect Ratios (L/D) >2000

Biopolymer Development Research Utilization of different vegetable oils, proteins, starches, etc. as building blocks for new resins

Hybridization

DDGS SFH SBP OH

Biomass Supply Stability Hybrid Biofiller

Hybridization Strategy

• Focus on the influence constituent content has upon the strength and modulus of a single loaded polymer

• Various blends to isolate role of individual constituents, as well as validate whether blend hybridization is feasible

Ash (%)

Protein (%)

Lignin (%)

Cellulose (%)

Hemicellulose (%)

Starch (%)

Calcium (%)

Phosphorus (%)

Fat (%)

Oat Hull 6.87 5.5 5.19 26.86 30.3 5.43 0.07 0.17 1.95 Sunflower Hull 2.77 4.6 21.68 42.37 16.69 0 0.17 0.1 1.7 DDGS 4.05 25.88 1.73 9.27 28.53 1.43 0.02 0.76 11.04 Sugarbeet Pulp 6.89 7.01 1.68 23.06 18.76 0 1.15 0.08 0.01 Corn Cob 3.48 2.43 4.54 30.83 34.52 5.56 0.03 0.06 0.16 Corn Chaff 0.86 11.49 1.03 8.76 25.85 39.47 0.05 0.21 3.5

*Initial study conducted

with 20 w/w

*Compounded in PP, ABS, & PP w/MAPP

Hybridization – Elastic Modulus Potential

ABS PP

Hybridization – Tensile Strength Potential

ABS PP

PP with MAPP

Hybridization – Tensile Strength Potential with Compatibilizer

• Maleic anhydride grafted PP (MAPP) – Maleic anhydride (MA) reacts with

hydroxyl groups in cellulose, forming CO bonds

– PP in MAPP co-crystallizes with matrix PP

Predictive Model Production

• Examined two filler types at 10, 20, 30 and 40 w/w loading

• 5 base polymer matrices: – Polypropylene (PP)

with and without MAPP compatibilization – Linear Low Density Polyethylene (LLDPE)

with and without MAPE compatibilization – Acrylonitrile Butadiene Styrene (ABS) – Poly(methyl methacrylate) (PMMA) – Polylactide (PLA)

Ash (%)

Protein (%)

Lignin (%)

Cellulose (%)

Hemicellulose (%)

Starch (%)

Calcium (%)

Phosphorus (%)

Fat (%)

DDGS 4.05 25.88 1.73 9.27 28.53 1.43 0.02 0.76 11.04 Corn Cob 3.48 2.43 4.54 30.83 34.52 5.56 0.03 0.06 0.16

Elastic Modulus Model

where d is a function of the matrix elastic modulus

Where Ec,ideal is a modified version of Einstein’s linear predictive single phase model, and Ec,FP is the change in modulus due to fat and protein content

and

where FP is the combined fat and protein content

Modulus Model Fitting

ABS PMMA

PLA

Modulus Model Fitting - Polyolefins

PP LDPE

Strength Fitting – Model Development

• Most promising modeling approach is a hyperbolically modified exponential model developed by Pukánszky et al. out of Budapest University of Technology and Economics

• Relies upon an empirical constant, B, which is used to

adjust (without any direct correlation) for interfacial adhesion, particle surface area, and particle density – Adjustment of this constant allows the model to be tailored to

make adequate fits on nearly all of the biobased specimens – However the constant can not be predictably determined easily

• B inherently must be tied to empirical measurements, however it can be modified to adjust for any given lignocellulosic filler

• These yield final equations which, when applied to the exponential model, can be used to predict for any change in filler type after

Strength Model Development

for non-modified

for compatibilized where Cell is the cellulose content

ABS PMMA

PLA

Tensile Strength Model Fitting

Tensile Strength Model Fitting - Polyolefins

PP LDPE

Torrefaction Strategy

• Torrefying biomass for storage or energy purposes is not a new concept...

• However, torrefying biomass for the purposes of high temperature biocomposites is new.

• Allows us to compound biomass into Nylon, ABS, PS, etc.

Flexural Property Results: TFS

Heat Deflection Temperature: TFS

Moisture Uptake: TFS

Biocomposite Product Trials To-Date

Biocomposite materials from NDSU are being/have been evaluated by different molding facilities throughout the U.S.

– Mellet Plastics, Fargo, ND – Steinwall Incorporated, Coon Rapids, MN – General Pattern, Blaine, MN – Falcon Plastics, Brookings, SD – Great Plains Plastic Molding, Fargo, ND

*Trial structural step parts produced with NDSU biocomposite material by Great Plains Plastic Molding

Biocomposite Trial: John Deere Company

• Developing biocomposite injection molded handles for John Deere tractor equipment

• Steinwall, Inc. is the molder for several John Deere parts (35,000 lb/yr)

The latest trial incorporated

30wt% ag filler in polypropylene

Biocomposite Trial: Shur-Co

• Falcon Plastics (Brookings, SD) currently molds the Shur-Co (Yankton, SD) handle out of Nylon 6,6 (5,000 lb/yr)

• These handles are used on a variety of roll-tarp applications for agricultural transportation equipment

• The handle must be impact and weather resistant as well as self-lubricating to rotate over a metallic central core

Handles have been molded and are now being tested for performance and endurance

Biocomposite Trial: Bobcat Company

Developing and analyzing biocomposite material solutions to existing and future

Bobcat skid steer loader equipment

Role in the Collaboration • Identify candidate

biocomposite material applications

• Develop biocomposite formulations for interior applications

• Perform physical tests on biocomposite materials and designs for verification

• Prototype biocomposite parts for field testing

Hyundai Project

Meetings with Hyundai have generated a high level of interest.

The Composites Innovation Centre (CIC) of Winnipeg, MB, Canada is managing the project.

A target part has been identified and we are currently formulating two biocomposite materials for trial.

Biocomposite Project Areas

Short Natural Fiber Research Utilization of “waste” cellulose fiber: DDGS, sunflower hull, sugar beet pulp, oat hull, etc.

Long Natural Fiber Research Utilization of residual flax, hemp, grasses, etc.: Aspect Ratios (L/D) >2000

Biopolymer Development Research Utilization of different vegetable oils, proteins, starches, etc. as building blocks for new resins

Biocomposite Trial: AGCO Corporation

10 ft Steel Boom

10 ft Composite Boom

Less Soil Compaction Improved Fuel

Economy Longer Spans Corrosion Resistant

Development of lightweight

sprayer booms

Sprayer Boom Tip Prototypes

30’ Boom Design in FEA

Biocomposites Strategy for Pultruded Composites

Hybridization of Long Fiber Biocomposites

Lay-up Layer Thickness (mm)

Layer Areal Density (g/m2)

Carbon fiber 0.48 448 Flax fiber 1.03-2.54 320-972

Carbon Fiber 0.48 448 Flax Fiber 1.03-2.54 320-972

Carbon Fiber 0.48 448

Fiber volume fractions (%)

Flax:Carbon Weight Ratio Carbon Fiber Flax Fiber

0.5:1 24 15 1:1 17 21

1.5:1 12 24 Plain Carbon 52 0

Plain Flax 0 29

Carbon Fibers

Flax Fibers

Testing Results vs. Theory

Prediction of Tensile Modulus based on simple rule-of-mixtures approach

Additional Results

Impact Results

3pt Bend Flexural Results

Biocomposite Project Areas

Short Natural Fiber Research Utilization of “waste” cellulose fiber: DDGS, sunflower hull, sugar beet pulp, oat hull, etc.

Long Natural Fiber Research Utilization of residual flax, hemp, grasses, etc.: Aspect Ratios (L/D) >2000

Biopolymer Development Research Utilization of different vegetable oils, proteins, starches, etc. as building blocks for new resins

Epoxidation of Sucrose Ester Resins

O

O

O

OO

OOO

O

OOO

OO

OOO

O O

O

O

OO

OOO

O

OOO

OO

OOO

O

O

O

O

O

O

O

O

OO

O

O

OO

H2O2 , Acetic acid

Amberlite 120H

• Prilezhaev reaction • Near 100% conversion of double bonds to epoxies

– No side reactions

Epoxy The average degree of sucrose

substitution

Average molecular

weight, MW (g/mol)

Epoxide equivalent

weight, EEW (g/eq.)

Epoxide functionality per molecule

Viscosity (mPa-s)

Density (g/cm3)

ESL 7.7 2,700 183 15.0 8000 1.05

ESSF 7.7 2,645 230 11.6 5000 1.04

ESS 7.7 2,628 248 10.6 2200 1.02

ESSB6 6 2,048 256 8.0 5500 1.03 ESO

(Control) 3 993 231 4.3 420 0.99

ESE Resins: A Platform Technology

Photo-polymerization

Thermal Crosslinking - Anhydrides

Polyols

Crosslinking (Meth)acrylates

O

O

O

O

O

O

O

O

OO

OO

O

O

O

O

O

OO

O

O

O

O

O

O

OO

O

O

O

O

Anhydride Curing of ESS Resins

OO OCrosslinker: Methyl hexahydrophthalic anhydride (MHHPA)

N

NCatalyst: 1,8-diazabycyclo [5.4.0] undec-7-ene (DBU)

Tensile Properties – MHHPA Cured ESS Resins

Epoxy compound

Modulus (MPa)

Tensile strength

(MPa)

Elongation at break

(%)

Tensile toughness (J)

X 103

ESL 1395 ± 191 45.8 ± 5.4 5.7 ± 2.6 8.44 ± 3.5

ESSF 909 ± 179 31.5 ± 3.2 8.5 ± 2.7 11.5 ± 6.3

ESS 497 ± 38 20.3 ± 4.3 21.7 ± 7.8 29.4 ± 9.2

ESSB6 1002 ± 52 35.1 ± 3.6 5.4 ± 0.7 9.1 ± 3.8

ESO (Control) 65 ± 10 10.2 ± 2.5 167 ± 19 97 ± 13.8

Epoxy compound

Epoxide/anhydride (equivalent ratio)

Modulus (MPa)

Tensile strength

(MPa)

Elongation at break (%)

ESS 1:0.5 170.8 ± 12.8 7.8 ± 0.4 11.0 ± 1.8

ESS 1:0.75 595.1 ± 8.2 21.8 ± 1.4 6.2 ± 1.0

ESSB6 1:0.5 231.8 ± 40.5 8.9 ± 1.6 10.4 ± 2.2

ESSB6 1:0.75 643.9 ± 26.1 19.6 ± 5.7 4.5 ± 0.7

ESO (Control) 1:0.5 5.0 ± 0.16 1.2 ± 0.1 27.9 ± 3.6

ESO (Control) 1:0.75 97.7 ± 28.7 6.0 ± 0.5 28.7± 5.6

Center for Biocomposite Research & Engineering

• To kick-start the development of the CBRE at NDSU, $265,000 from the ND Corn Council was secured to purchase a large, production scale twin-screw extruder and accessories to support current biocomposite trials with JD, Shur-Co, AGCO, Bobcat, etc.

• Several other entities are being be solicited to contribute to the CBRE for other equipment, but ND Corn Council contribution is the “seed” to launch the center.

CBRE - Pilot Plant Vision

• Large Scale R&D Biocomposite Compounding Facility • 5,000 sqft (Location – SpaceAge Synthetics, Inc., Fargo, ND) • 1-2 Technicians + Research Students (Research Funding) • Major Equipment

– Biomass & Polymer Storage – Biomass Milling/Grinding – Biomass Drying/Mixing/Metering – Pressurized Conveying System – Compound Extruder w/ Pelletizer – Pultrusion Line – Natural Fiber Mat Production Line – Biocomposite Drying – Biocomposite Metering/Bagging – Dust Vacuum System – Large Air Compressor – Microwave Ashing Unit

Acknowledgements and Continued Partners

• NDSU College of Engineering & Architecture/Mechanical Engineering Department – Existing equipment and facilities will be included in the center – Educational and research time of interested faculty will be encouraged

• NDSU College of Agriculture, Food Systems and Natural Resources/NDSU Extension and Experiment Station – Existing Agricultural Pilot Plant facilities will closely collaborate with the center – Sharing of ag-based materials knowledge and knowhow

• SpaceAge Synthetics Contribution (Fargo, ND) – Space allocation for the biocomposite pilot plant facilities – Continued collaboration regarding biobased foam and biocomposite technology

• Tecton Products (Fargo, ND) – Collaboration regarding pultrusion technology for various companies

• Composites Innovation Centre (Winnipeg, MB) – Continued collaboration on biocomposite development for various companies

• Other existing companies we have been working with – AGCO, John Deere Co., Steinwall, Inc., Shur Co., Falcon Plastics, Inc., GVL Poly, etc.

• Other commodity groups – AmeriFlax, Soybean Council, Oilseed Council, Sugarbeet Growers, etc.