Polymer Blends and Composites...This course introduces students to multicomponent polymeric systems,...

Polymer Blends and Composites from Renewable Resources

Assoc.Prof. Dr. Jatuphorn Wootthikanokkhan School of Energy, Environment and Materials,

King Mongkut’s University of Technology Thonburi (KMUTT), Thailand

School of Energy, Environment and Materials

KMUTT

About this course

MTT692 Special Topics: Polymer Blends and Composites from Renewable Resources

Course description

This course introduces students to multicomponent polymeric systems, particularly those based on blends and composite materials. Specifically, this course focuses on the use of natural and renewable materials such as cellulose micro/nano fibers, biodegradable aliphatic polyesters, thermoplastic starch and natural rubber. Fundamental concepts and mechanisms related to the development of blends and composites materials will be described. Case studies involving compounding formulations and applications of some selected polymer blends and composites systems will also be introduced and discussed.

MTT692 Special Topics: Polymer Blends and Composites from Renewable Resources

Objectives:

By the end of this course, the students should be able to;

1) Understand the fundamental concepts of blends and composites 2) Understand structure-properties relationships of polymer blend and composites

3) Identify techniques that can be used for preparing and fabricating polymer blends and composites

Lecturers:

Assoc.Prof.Dr.Jatuphorn Wootthikanokkhan (65%) (JWN)

Dr. Supachok Tanpichai (28 %) (STI) Assoc.Prof. Ekachai Wimolmala (7%) (EWA)

Measurements

Lecturers

Midterm exam.

Final exam.

Presentation &

Report

Total

Assoc.Prof.Dr.Jatuphorn Wootthikanokkhan

40

5

20

65

Dr. Supachok Tanpichai

-

30

-

30

Assoc.Prof. Ekachai Wimolmala

-

5 -

5

Textbooks & References 1. W.J. Work, K. Horie, M. Hess, R.F.Stepto, Definitions of terms related to polymer blends, composites, and multiphase polymeric materials, Pure Appl.Chem. 76(2004)1985-2007 2. L.Yu, K. Dean, L.Li, Polymer blends and composites from renewable resources, Prog. Polym. Sci, 31(2006)576-602. 3. Polymeric Multicomponent Materials, edited by L.H.Sperling, John Wiley & Sons, Inc., Canada, 1997 4. Polymer Blends and Alloys, edited by M.J.Folkes and P.S.Hope, Chapman & Hall, UK, 1993 5. Rubber Toughened Engineering Plastics, edited by A.A.Collyer, Chapman & Hall, Great Britain, 1994 6. Polymer Toughening, edited by C.B.Arends, Marcel Dekker, Inc., USA, 1996 7. Polymer Blends, edited by D.R.Paul et.al, Academic Press, USA, 1978 8. Polymer Blends, edited by D.R.Paul and C.B.Bucknall, John Wiley & Sons, USA, 2000 9. J.S.Miles & S.Rostami, Multicomponent Polymer Systems, Longman Scientific & Technical, Great Britain, 1992. 10. An introduction to composite materials by D Hull 11. Introduction to polymers by Robert J Young 12. Engineering mechanics of composite materials by Isaac M Daniel 13. Fiber-reinforced composites : materials, manufacturing, and design by P. K Mallick 14. Polymer nanocomposites : processing, characterization, and applications by Joseph H Koo 15. Polymer nanocomposites : synthesis, characterization, and modeling by Krishnamoorti and Richard A Vaia 16. Polymeric foams : science and technology byShau-Tarng Lee 17. The Science and Technology of Rubber by Jame E. Mark, Burak Erman & C. Michael Roland, 4th Ed., Elsevier, Oxford, UK, 2013 18.Handouts.

JWN

14/01/59

Introduction

Polymers from renewable resource, miscibility and compatibility in polymer blends, types of morphology of immiscible blends

JWN

21/01/59

Thermodynamic of polymer blend Gibbs free energy equation, Role of solubility parameter, determinations the solubility parameter (by calculating via a group molar attraction constant and/or by experiments), factors affecting polymer miscibility & the phase diagram , assessments of polymer–polymer miscibility

JWN

28/01/59

Compatibilizers and compatibilization Types of compatibilizers (block- graft- copolymers), some common compatibilizers and their preparation methods, effects of compatibilizers on structure and properties of polymer immiscible blends, characterization of interdiffusion and interfacial profiles, reactive compatibilization

JWN

04/02/59 Blending techniques, melt blending, solution blending, IPNs, reactive blending, freeze dry blending

JWN

11/02/59

Rubber toughened plastics Structure of rubber toughened plastics and toughening mechanisms, role of particle size, ligament thickness, rubber volume fraction and cross-linking of the rubber phase, percolation model, interfacial model, particle concentration model,

JWN

18/02/59

PLA and the related blends, toughening of PLA, impact modifiers for PLA, structure-properties relationships of rubber toughened PLA, PLA/starch blends, thermoplastic starch, compatibilizer for PLA/starch blends, reactive blending, structure-properties relationships of PLA/starch blends

JWN

25/02/59

Summary & review

03/03/59 Midterm Examination

JWN

10/03/59

Natural rubber blends Effect of mal-distribution of crosslink on properties of elastomer blends, determination of

crosslink distribution in elastomer blends, Factors affecting distribution of curatives, effects of distribution of carbon black on properties of elastomer blends, determination of distribution of carbon black in elastomer blends, factors affecting carbon black distribution

EWA

17/03/59

Applications of natural rubber and elastomer blends

Selected materials based on elastomer blend for oil resistant properties and progress in developments of materials for natural rubber roofs composite applications.

STI

24/03/59

Introduction to green composites

Definition, advantages and disadvantages and limitation of the green composites

STI

31/03/59

Cellulose micro/nano fiber as a reinforcing agent

Compositions, types and properties of cellulose nanofibers and preparation method STI

07/04/59

Processing & applications of green composites

Processing techniques and applications STI

21/04/59

Structure-properties relationships of green composites

Rule of mixtures, reinforcement distribution, interaction of the matrix and reinforcement

JWN, STI, EWA

28/04/59

Student presentations

on structure-properties-applications relationship of some recently developed polymer blends and green composite for commercial uses.

12/05/59 Final Examination

Dr.J.Wootthikanokkhan, KMUTT

Definitions

“A polymer blend is a member of a class of materials analogous to metal alloys, in

which at least two polymers are blended together to create a new material with different

physical properties.” [Gert R. Strobl (1996). The Physics of Polymers Concepts for Understanding Their

Structures and Behavior]

“Composite is a multicomponent material comprising multiple different (nongaseous)

phase domains in which at least one type of phase domain is a continuous phase”

“Polymer composite refers to the composite in which at least one component is a

polymer” (W.J.Work et al., Pure Appl. Chem. 76(2004)1985-2007)


Varieties of polymers architecture and their combinations


Some reasons for blending

Enhancement of physical properties of some polymers

Improving process-ability of some polymers Economy purpose Recycling


Santoprene (Thermoplastic vulcanizate [TPV] based on PP/EPDM)

(Ref: Asian plastic news, october, 2005)


Makroblend (PC/PET blend) from Bayer

Better thermal stability, chemical resistance, paint-ability

REF: Asian plastic news, september, 2005


Advantages of polymer blending

Relative ease of blending techniques as compared to synthesis of new polymers.

Large scale production is cheaper than polymer synthesis

More environmental friendly process than the synthesis (lower

usage of solvents and monomers)

Classification of polymer blends

(Adapted from “Polymer Alloy Compendium; A Technical note from JICA short course in High Performance

Polymer Technology”)

Terms related to polymer blend miscibility (Ref. form Utracki, in Polymer Blend Handbook, 2002, p. 135, ch. 2, Kluwer Academic Publisher.)

Term Definition

Miscible polymer blend Polymer blend, homogeneous down to the molecular level, in which the domain size is comparable to macromolecular dimension.

Immiscible blend Polymer blends whose change in free energy of mixing is greater than zero.

Polymer Alloy Immiscible, compatibilized polymer blend with the modified interface and morphology

Interphase Third phase in binary polymer alloys, endangered by inter-diffusion or compatibilization. Its thickness ~ 2 to 60 nm, depends on polymer mescibility and compatibilization

Compatibilization Process of modification of the inter-phase in immiscible polymer blends, resulting in reduction of the interfacial energy, development and stabilization of the desired morphology, leading to the creation of a polymer alloys with enhanced performance


Examples of some miscible and immiscible blends

Miscible blends

– PS/PPO, – PVC/NBR, – PVC/polyesters, PET/PBT, – PVDF/PMMA

Immiscible blends

– High impact polystyrene (HIPS) (PS+ polybutadiene),

– PE/PP


Some types of morphology in immiscible blends

Dispersed particle morphology

A desired structure for toughening plastics

Sub-inclusion or composite droplet

Co-continuous morphology

Like a water soaked sponge, both phase are continuous

Fibrillar morphology


PS/polybutadiene immiscible blend


TEM micrograph of PVC/MBS blend stained with OsO4 (Ref: Encyclopedia of PVC, LI. Nass et.al., Marcel Dekker, NY, 1988)


Morphology changes with composition

Morphology of NR/ACM (50/50 % w/w) blend


Fibrillar morphology

SEM micrograph showing morphology of NR/ACM (20/80 % w/w) blend


Dispersed particle morphology with sub-inclusion of PS phase in rubber particles

Miscibility and compatibility of blends

Miscible & Immiscible blends (Classified on the basis of phase separation and phase size)

Compatible- and Incompatible blends (Classified on the basis of interfacial adhesion and mechanical strengths)

Tg and Tm values (from DSC) of PVDF/PMMA blends [Ref: Polymer Science and Technology, J.R. Fried,, 1995]

SEM micrograph showing poor interfacial adhesion in PS/PE blend [Ref: E. Grulke, Polymer Process Engineering, 1993]


Compatibilization of incompatible blends using block- and graft copolymers

SEM micrograph showing a better interfacial adhesion in PS/PE blend after adding hydrogenated STYRENE-BUTADIENE block copolymer [Ref: E. Grulke, Polymer Process Engineering, 1993]


Effects of block copolymer on morphology and mechanical properties of NR/ACM

Materials from renewable resources


Monomers, polymers and composites from renewable resources

This course focuses on the following high potential materials; Poly(lactic acid) as a biodegradable plastic

Starch as a thermoplastic material

Cellulose and bacteria cellulose for uses as both reinforcing agents for

composites AND standalone films/sheets Natural rubber as bio-based elastomeric materials


Definitions

• Renewable resources may be defined as resources (solar, soil trees) that have the potential to be replaced over time by natural processes.

• Biomass is the material of biological origin, excluding materials embedded in geological formation and/or fossilized

• Bio-based means derived from biomass • Bio-based product refer to the product which is wholly or partly bio-

based

• Biodegradable plastics are plastics that decompose by the action of living organisms, usually bacteria

Biopolymers versus biodegradable polymers

Biopolymers include PLA, natural rubber Not all biopolymers are biodegradable On the other hand, some synthetic polymers can also be

biodegradable such as PCL, PBS

Classification of biodegradable polymers

(Adapted from L. Averous, J.Macromol.Sci., Polym.Rev.C4(3)2004, 231-274)

Comparisons of some biodegradable polymers

Polymer Performance factors

Advantages Disadvantages Potential applications

Starch Ratio of amylose to amylopectin

Low cost, rapid degradation

Hydrophilicity There are a number of applications where biodegradable polymers would be desirable, including disposable food items, bags, foam, agricultural film, and some injection molded products. Most of these items are currently produced from PE and PS.

Cellulose acetate Degree of substitution

Tensile strength DS > 2.2 reduces biodegradation

PHA Side-chain length, copolymer ratio

Rapid biodegradation, water stable

Cost

PVOH Molecyular weight, percent hydrolysis

Good oxygen barrier, rapid biodegradation

Solubility in water

PCL Molecular weight, crystallinity

Water stable, biodegradable, toughness

Low melting point

PLA D:L ratio, molecular weight

Tensile strength, clear film

Brittle

PLA as a biodegradable polymer

Cost and production level of some biodegradable polymers

Polymer Cost ($ per lb)*

Principal mode of production

Production level (lb per years) *

Starch 0.15 - 0.80 Plant biomass > 230 billion

Cellulose acetate 1.70 Chemical modification of polysaccharides (cotton,

wood pulp)

2.3-2.4 billion

Poly(hydroxybutyrate-co-valerate

6.00 - 8.00 Bacterial fermentation 660,000

PVOH 1.50 - 2.50 Polymerization of vinyl alcohol

150-200 million

Polycaprolactone (PCL)

2.70 Polymerization of caprolactone

< 10 million

Poly(lactic acid), [PLA]

1.00 – 3.00 Polymerization of lactic acid

10 million

* Ref: Trends in Polymer Science, 2 (1994) 230

Physical and mechanical properties of some biodegradable polymers

Polymer Tg

(°C)

Tm

(°C)

Td

(°C)*

Tensile Strength

(MPa)

Elongation

(%)

PHA (- 50) – (+5) 54 -175 - ≤ 40 No data

PHB 5 175 - 40 -

PHBV (12 % V) - 138 297 25 20

PHBV (24 % V) - - - 15 -

PHOct (-35) 55 290 9 380

PVA (or PVOH) 58 – 85 180 – 240 - 40 – 50 300 – 400

PCL -60 55 – 65 250 21 – 31 600 – 1000

PLA 50 - 59 130 - 196 245 50 3


Materials used for the production of lactic acid

35

From lactic acid to lactides

36

• Lactide is obtained by depolymerization of low Mw PLA to give a mixture of D

and L lactide (or meso Lactide)

• The differences percentage of lactide isomer formed depends on lactic acid

isomer feedstock, temp. and catalyst.

• A mixture of D and L lactide (1/1) can form racemic stereocomplex which melt at 230 °C

and have superior mechamical properties than either pure polymers

PLA Polymerization

37

Degradation of PLA

Commercial PLA

• Commercial PLA such as NatureWorks® are copolymer of PLLA and PDLLA,

• Various grades are available with different in terms of D-lactide content

• 4032-D (1-2 % D-lactide) • 4042-D (3-5 % D-lactide) • 4060-D (11-13 % D-lactide)

• PLA resins of high D-content (4-6%) would be more suitable for thermoformed, extruded, and blow molded.

Comparison between PLLA and PDLLA

Polymer Crystallinity Tg (°C) Degradation Rate

PLA (L form)

Semi Crystalline (Tm = 173-178 °C)

60-65 > 2 Years

PLA (D,L form)

Amorphous 55-60 12-16 months

Last retrieved on February, 2012 http://www.drugdeliverytech.com/ME2/dirmod.asp?sid=&nm=&type=Publishing&mod=Publications%3A%3AArticle&mid=8F3A7027421841978F18BE895F87F791&tier=4&id=BB85E8579021481EACBC7C3F0674348F 40

ผลของ stereochemistry และ crystallinity

ตอสมบตเชงกลของ PLA

(From Garlotta, 2002) 41

ผลของ stereochemistry

ตอสมบตทางความรอนของ PLA

(From Lim et al., 2008) 42

Applications of PLA

43

Processing of PLA

Extrusion

Extrusion blown film process Injection moulding

Injection stretch blow moulding

Thermoforming 44

Problems of PLA

1. PLA is brittle 2. Melt strength of the PLA is inherently low 3. Cost of the PLA is relatively high 4. PLA is thermally unstable, it can be degraded during the processing

due to; • Hydrolysis • Chain scission

Some polymers used for blending with PLA

Patents Polymers Purpose

US patent 7,354,973 B2 Ethylene copolymers (EGMA, EPDM, EBA, Ionomer)

Toughening

US Patent 5,498,650 (1996) US patent 7,138,439 (2006)

Copolyesters

US Patent 7,368,503 (2008) PCL (with P(MMA-co-GMA) as a compatibilizer)

US Patent 7,393,590 B2 (2008) PCL using peroxides as a

compatibilizer

US Patent 5,922,832 Epoxidized Natural Rubber & MA-g-PB (reactive compatibilizer)

US Patent 7,214,414B2 Ecoflex, Biomax

Impact strength & processability,

US Patent 5,939,467 [1999] PCL Aliphatic polyester PU

Rheological properties (melt

strength, viscosity)

Some commercial impact modifiers for PLA

Trade Name Manufacturers Chemistry of the materials

Comments

Biostrength®130 Arkema Core-shell particle Impact modifier (Transparent)

Biostrength®150 Arkema Core-shell particle

Impact modifier (Opaque)

Biostrength 700 Arkema Acrylic copolymer •Melt strength enhancer •Transparency is maintained

Biomax®Strong 100

DuPont Ethylene copolymer Impact modifier for PLA. Non-food packaging

Biomax®Strong 120

DuPont Ethylene copolymer Impact modifier for PLA Food packaging

EMforce®Bio Specialty mineral Impact modifier

Paraloid [BPMS250] Rohm and Haas Acrylic polymer •No effect on film clarity •FDA and EU (Directive2002/72/EC) approved

Starch as a thermoplastic materials

48

Structures of starch granule

Phase transitions of starch

Adapted from M.B.K.Naizi, also available from http://www.rug.nl/research/portal/files/6572065/08_diss.pdf (January, 2016)

http://www.rug.nl/research/portal/files/6572065/08_diss.pdf





ภาพถาย SEM ของแปงปกตและแปงเทอรโมพลาสตก

51 Thermoplasic starch, TPS Normal starch (un-modified)

700x

400x

THERMOPLASTIC STARCH: DEFINITION AND PROPERTIES

Plasticizers for TPS

Water (Hulleman et.al., 1998) Glycerol (Rosa et.al., 2007, 2009) Sorbitol (Yang et.al., 2006, Bourtoom, 2008) Urea (Ma et.al., 2004, 2006) Citric acid (Wang et.al., 2007) Formamide (Ma et.al., 2004)

TPS containing only water has poor mechanical properties The plasticizers intereac with starch molecules via a hydrogen bonding

Physical and mechanical properties of some biodegradable polymers

Polymer Tg (°C)

Tm (°C)

Td (°C)*

Tensile Strength

(MPa)

Elongation (%)

Starch 230 220-240 220 NT NT

Starch (7% H2O) 140 - - NT NT

Starch (7% H2O)

18 - - NT NT

Cellulose acetate (DS = 2.5)

190 230-250 - 17-50 10-30

* Td = decomposition temp.

** NT = not testable


TPS blends

TPS is blended for mainly two purposes; 1. To improve such its properties as water resistance and

mechanical performance

2. To use it as a modifier for other polymers, with the purpose of increasing the biodegradability and/or decreasing the cost of the blends

Derivatives of polysaccharide

Cellulose acetate is obtained by reacting cellulose with acetic anhydride Degree of substitution is expressed as DS. The maximum value of DS = 3 for

polysacharide The cellulose acetate has tensile strength comparable to polystyrene, which make the

polymer suitable for injection moulding

The rate of biodegradation decrease with the DS value

Various acylating agents

Acylating agents Disadvantages

Acetic anhydride

Prohibited

Propionic anhydride Expensive

Maleic anhydride Staining, induced crosslinking

Acyl halides Less reactive than anhydrides

Natural rubber as a source of bio-based elastomeric products

Classification of rubbers

Rubbers

ยางธรรมชาต (ยางพารา)

Natural Rubber

ยางสงเคราะห

Synthetic Rubbers

นอกจากนน ยางสงเคราะห ยงสามารถแบงยอยไดดงน

1. ยางสาหรบงานทวไป (Commodity rubbers) เชน IR (Isoprene Rubber) BR (Butadiene

Rubber)

2. ยางสาหรบงานสภาวะพเศษ (Specialty rubbers) เชน การใชงานในสภาวะอากาศรอนจด

หนาวจด หรอ สภาวะทมการสมผสกบนามน ไดแก Silicone, Acrylate rubber เปนตน

Natural rubber Polyisoprene, high green strength, low cost. But poor oil & heat resistance

Synthetic rubbers

SBR, BR, IR Oil and heat resistance rubber e.g. NBR, AR(ACM), FKM

Assoc. Prof. Dr. Jatuphorn Wootthikanokkhan, KMUTT

Natural rubber (cis 1,4-polyisoprene)

Chemical structure of NR based on Gutta Percha (trans-1,4-

polyisoprene) (a) and Heavea Rubber (cis-1,4- polyisoprene) (b)

Chemical structure of NR based on Gutta Percha (trans-1,4-polyisoprene) (a)

and Heavea Rubber (cis-1,4- polyisoprene) (b)

(a)

(b)


Stereoisomers of 1,4-polyisoprene (a) cis, (b) trans

Figure from S.L. Rosen, Fundamental principles of polymeric materials, John Wiley & Sons, 1993, p. 36

Compositions of NR latex

Composition Content (%)

Rubber 30.0-40.0

Protein 2.0-2.5

Organic compound 2.0-3.0

Ash 0.7-0.9

Water 55.0-60.0

] R.K. Han, in Rubber Engineering, Chapter 9, McGraw-Hill, New York, 2001, pp. 425-432.


จะตองนานายางมาผานกระบวนการซงม ขนตอนดงน

– เตมโซเดยมเมตะไบซลไฟทลงในน ายางเพอเพมความขาว

– เตมกรดฟอรมคหรอกรดอะซตคเพอใหเนอยางตกตะกอนและจบตว

เปนกอนทงไวเปนเวลา 10-12 ชวโมง

– นาเนอยางทไดไปทาการรดใหเปนแผน จากนนทาการรมควนตอไป

การเกด cross-linking ในยาง

• ในทน คาวา Curing, Crosslinking, และ

Vulcanization มความหมายเดยวกน

• สวนใหญ อาศยปฏกรยาเคม และความรอน

กระตน

• อาจจะทาในโมลด (mould) ในระหวางขนตอน

การขนรป หรออาจจจะทาในเตาอบ (hot air

oven) หลงขนรปแลวกได


Cross-linking systems for elastomers

Elastomers Cross-linking systems

Polychloroprene

MgO, ZnO with or without accelerator

Fluoroelastomer a) Diamine, or b) Bisphenol compounds, or c) Peroxide and triazine

Acrylate copolymers a) poly-or diamines, or b) Sodium stearate and sulfur

Carboxylate rubber

a) Metal oxide with or without sulfur b) Peroxides, or c) Epoxides and polyols

Polysiloxane a) Peroxide (high temperature), or b) Metal catalysts moisture (RTV)


ผลกระทบของปรมาณพนธะขาม • ผลของการเกดโครงสรางแบบ crosslink

– ทนการละลาย

– ทนความรอน

– มความยดหยน อลาสตก

สมบตของยางธรรมชาต

• มคาอณหภมการเปลยนสถานะคลายแกว (glass transition temperature, tg) ประมาณ

-70 องศาเซลเซยส

• มความทนทานตอนากรดเจอจาง ดาง และเกลอไดด

• มความสามารถในการยดตวไดสงและสามารถคนตวไดด ทงนเนองจากยางธรรมชาตม

นาหนกโมเลกลสงมาก และมสายโซโมเลกลทคอนขางยาวแลวมการพนกน (entanglement) ทาให

เกดการเชอมโยงในลกษณะโครงสรางตาขายแบบหลวม ๆ เมอไดรบแรงกระทาจากภายนอก จะทา

ใหสายโซโมเลกลทจากเดมพนกนอยมการยดตวตามทศทางของแรง และมการจดเรยงตวกนอยางม

ระเบยบสามารถเกดผลกได ดงนนยางธรรมชาตจงมสมบตเดนในดานของความแขงแรง


การนายางธรรมชาตไปใชงาน 1. เนองจากยางธรรมชาตมสมบตดเยยมในดานการทนตอแรง

ดงและมความยดหยนสงมากแมไมไดเตมสาร เสรมแรง จง

เหมาะทจะใชในการผลต ถงมอยาง ถงยางอนามย และ

ลกโปง เปนตน

2. ยางธรรมชาตมสมบตทงเชงกลและพลวตทด มความรอน

สะสมทเกดขณะใชงานตา และมสมบต ความเหนยวตดกนท

ด จงเหมาะทจะนาไปใชในการผลตเปน ยางลอรถบรรทก

หรอใชผสมกบยางสงเคราะหในการผลตลอรถยนต ฝายยาง

ยางกนกระเเทกทาเรอ เปนตน


ขอจากดของยางธรรมชาต • ยางธรรมชาตทมพนธะคทวองไวตอการเกดปฏกรยาอยดวย จง

สงผลกระทบในเรองของความสามารถในการตานทานตอ

ออกซเจน แสงแดด และโอโซนทตา โดยยางธรรมชาตจะ

เกดปฏกรยาออกซเดชนตรงบรเวณพนธะคได

• นอกจากนนการทโมเลกลของยางธรรมชาตประกอบ

ไปดวยอะตอมคารบอนและไฮโดรเจนเปนหลก จงทา

ใหโมเลกลของยางธรรมชาตจงมสภาพความเปนขว

ตา และมความสามารถในการทนตอนามนและตวทา

ละลายอนทรยทไมมขวไดต า


เปรยบเทยบสมบตดานการทนความรอนและนามนของยางธรรมชาตกบยางสงเคราะหชนดตางๆ

Elastomer blends and research issues

Uneven distribution of curatives in rubber-rubber blends

Mal-distribution of reinforcing fillers in the elastomer blends

Topics for next week

Thermodynamic of polymer blends Assessment of polymers miscibility

Polymer Blends and Composites...This course introduces students to multicomponent polymeric systems,...

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