Drobny Handbook of Thermoplastic Elastomers

2. Auflage 2014
ISBN: 978-0-323-22168-9
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 464 Seiten

Reihe: Plastics Design Library

Handbook of Thermoplastic Elastomers, Second Edition presents a comprehensive working knowledge of thermoplastic elastomers (TPEs), providing an essential introduction for those learning the basics, but also detailed engineering data and best practice guidance for those already involved in polymerization, processing, and part manufacture. TPEs use short, cost-effective production cycles, with reduced energy consumption compared to other polymers, and are used in a range of industries including automotive, medical, construction and many more. This handbook provides all the practical information engineers need to successfully utilize this material group in their products, as well as the required knowledge to thoroughly ground themselves in the fundamental chemistry of TPEs. The data tables included in this book assist engineers and scientists in both selecting and processing the materials for a given product or application. In the second edition of this handbook, all chapters have been reviewed and updated. New polymers and applications have been added - particularly in the growing automotive and medical fields - and changes in chemistry and processing technology are covered. - Provides essential knowledge of the chemistry, processing, properties, and applications for both new and established technical professionals in any industry utilizing TPEs - Datasheets provide 'at-a-glance' processing and technical information for a wide range of commercial TPEs and compounds, saving readers the need to contact suppliers - Includes data on additional materials and applications, particularly in automotive and medical industries

Jiri G. Drobny is President of Drobny Polymer Associates, and former Adjunct Faculty of Plastics Engineering at the University of Massachusetts, Lowell. Drobny is an active educator, lecturer, writer, and internationally known consultant. His career spans more than 40 years in the rubber and plastic processing industry, mainly in research and development with senior and executive responsibilities.

Autoren/Hrsg.

Drobny, Jiri George

Inhaltsverzeichnis

1;Front Cover;1
2;HANDBOOK OF THERMOPLASTIC ELASTOMERS;4
3;Copyright;5
4;Dedication;6
5;Contents;8
6;Preface to the Second Edition;18
7;Preface to the First Edition;20
8;Acknowledgments;22
9;1 - Introduction;24
9.1;1.1 Elasticity and Elastomers;24
9.2;1.2 Thermoplastic Elastomers;25
9.3;References;33
10;2 - Brief History of Thermoplastic Elastomers;36
10.1;References;37
11;3 - Additives;40
11.1;3.1 Antioxidants;40
11.2;3.2 Light Stabilizers;40
11.3;3.3 Nucleating Agents;41
11.4;3.4 Flame Retardants;42
11.5;3.5 Colorants;44
11.6;3.6 Antistatic Agents;46
11.7;3.7 Slip Agents;47
11.8;3.8 Antiblocking Agents;47
11.9;3.9 Processing Aids;47
11.10;3.10 Fillers and Reinforcements;47
11.11;3.11 Plasticizers;50
11.12;3.12 Other Additives;51
11.13;3.13 Selection of Additives;52
11.14;3.14 Health, Hygiene, and Safety;52
11.15;References;53
12;4 - Processing Methods Applicable to Thermoplastic Elastomers;56
12.1;4.1 Introduction;56
12.2;4.2 Mixing and Blending;64
12.3;4.3 Extrusion;78
12.4;4.4 Injection Molding;94
12.5;4.5 Compression Molding;116
12.6;4.6 Transfer Molding;120
12.7;4.7 Blow Molding;128
12.8;4.8 Rotational Molding;138
12.9;4.9 Foaming of Thermoplastics;152
12.10;4.10 Thermoforming;156
12.11;4.11 Calendering;161
12.12;4.12 Secondary Manufacturing Processes;161
12.13;4.13 General Processing Technology of Thermoplastic Elastomers;185
12.14;4.14 Process Simulation;188
12.15;4.15 3D Printing;188
12.16;4.16 Product Development and Testing;189
12.17;References;190
13;5 - Styrenic Block Copolymers;198
13.1;5.1 Introduction;198
13.2;5.2 Polystyrene–Polydiene Block Copolymers;199
13.3;5.3 Styrenic Block Copolymers Synthesized by Carbocationic Polymerization;212
13.4;5.4 New Commercial Developments;214
13.5;References;215
14;6 - Thermoplastic Elastomers Prepared by Dynamic Vulcanization;218
14.1;6.1 Introduction;218
14.2;6.2 The Dynamic Vulcanization Process;219
14.3;6.3 Properties of Blends Prepared by Dynamic Vulcanization;220
14.4;6.4 Processing and Fabrication of Thermoplastic Vulcanizates;224
14.5;6.5 New Commercial Developments;228
14.6;References;229
15;7 - Polyolefin-Based Thermoplastic Elastomers;232
15.1;7.1 Introduction;232
15.2;7.2 Thermoplastic Polyolefin Blends;232
15.3;7.3 Morphology;234
15.4;7.4 Properties of TPOs;234
15.5;7.5 Processing of TPOs;236
15.6;7.6 Painting of TPOs;239
15.7;7.7 New Commercial Developments;239
15.8;References;240
16;8 - Thermoplastic Elastomers Based on Halogen-Containing Polyolefins;242
16.1;8.1 Introduction;242
16.2;8.2 Blends of PVC with Nitrile Rubber;242
16.3;8.3 Blends of PVC with Other Elastomers;244
16.4;8.4 Melt-Processable Rubber;246
16.5;8.5 Thermoplastic Fluorocarbon Elastomer;253
16.6;8.6 New Commercial Development;254
16.7;References;254
17;9 - Thermoplastic Polyurethane Elastomers;256
17.1;9.1 Introduction;256
17.2;9.2 Synthesis of TPUs;257
17.3;9.3 Morphology;259
17.4;9.4 Thermal Transitions;260
17.5;9.5 Properties;260
17.6;9.6 Processing of TPUs;265
17.7;9.7 Blends of TPUs with Other Polymers;271
17.8;9.8 Bonding and Welding;272
17.9;9.9 Use of Bio-Based Raw Materials in TPUs;272
17.10;9.10 New Commercial Development;272
17.11;References;273
18;10 - Thermoplastic Elastomers Based on Polyamides;278
18.1;10.1 Introduction;278
18.2;10.2 Synthesis;278
18.3;10.3 Morphology;280
18.4;10.4 Structure–Property Relationships;281
18.5;10.5 Physical and Mechanical Properties;282
18.6;10.6 Chemical and Solvent Resistance;286
18.7;10.7 Electrical Properties;286
18.8;10.8 Other Properties;286
18.9;10.9 Compounding;287
18.10;10.10 Processing;288
18.11;10.11 Bonding and Welding;290
18.12;10.12 New Commercial Developments;291
18.13;References;291
19;11 - Thermoplastic Polyether Ester Elastomers;294
19.1;11.1 Introduction;294
19.2;11.2 Synthesis;294
19.3;11.3 Morphology;295
19.4;11.4 Properties of Commercial COPEs;295
19.5;11.5 COPE Blends;300
19.6;11.6 Processing;301
19.7;References;308
20;12 - Ionomeric Thermoplastic Elastomers;310
20.1;12.1 Introduction;310
20.2;12.2 Synthesis;311
20.3;12.3 Morphology;311
20.4;12.4 Properties and Processing;311
20.5;12.5 Applications;313
20.6;References;313
21;13 - Other Thermoplastic Elastomers;314
21.1;13.1 Elastomeric Star-Block Copolymers;314
21.2;13.2 TPEs Based on Interpenetrating Networks;316
21.3;13.3 TPEs Based on Polyacrylates;317
21.4;References;318
22;14 - Thermoplastic Elastomers Based on Recycled Rubber and Plastics;320
22.1;14.1 Introduction;320
22.2;14.2 EPDM Scrap;320
22.3;14.3 NBR Scrap;320
22.4;14.4 Recycled Rubber;321
22.5;14.5 Waste Latex;321
22.6;14.6 Waste Plastics;321
22.7;References;321
23;15 - Applications of Thermoplastic Elastomers;324
23.1;15.1 Introduction;324
23.2;15.2 Applications for Styrenic Thermoplastic Elastomers;325
23.3;15.3 Applications of Thermoplastic Vulcanizates;333
23.4;15.4 Applications of Thermoplastic Polyolefins;337
23.5;15.5 Applications of Melt-Processable Rubber;339
23.6;15.6 Applications of PVC Blends;342
23.7;15.7 Application of Thermoplastic Polyurethanes;343
23.8;15.8 Application of Thermoplastic Polyether Ester Elastomers;348
23.9;15.9 Applications of Polyamide Thermoplastic Elastomers;350
23.10;15.10 Applications of Ionomeric Thermoplastic Elastomers;353
23.11;15.11 Applications of Other Thermoplastic Elastomers;356
23.12;References;357
24;16 - Recycling of Thermoplastic Elastomers;362
24.1;16.1 Introduction;362
24.2;16.2 Recycling Methods for Thermoplastic Elastomers;362
24.3;References;363
25;17 - Recent Developments and Trends;364
25.1;17.1 Current State;364
25.2;17.2 Drivers for the Growth of TPEs;364
25.3;17.3 Trends in Technical Development;365
25.4;17.4 Other New Developments;367
25.5;References;367
26;Appendix 1: Books and Major Review Articles;370
26.1;Books;370
26.2;Major Review Reports and Articles, Conferences;370
26.3;Recent Conferences;371
27;Appendix 2: Major Suppliers of Thermoplastic
Elastomers and Compounds;372
28;Appendix 3: ISO Nomenclature for
Thermoplastic Elastomers;378
28.1;Generic Terms and Definitions;378
28.2;Nomenclature System;378
28.3;Polyamide TPEs (TPAs);378
28.4;Copolyester TPEs (TPCs);379
28.5;Olefinic TPEs (TPOs);379
28.6;Styrenic TPEs (TPSs);379
28.7;Urethane TPEs (TPUs);379
28.8;Dynamically Vulcanized TPEs (TPVs);379
28.9;Miscellaneous Material (TPZ);380
29;Appendix 4: Processing Data Sheets for Commercial
Thermoplastic Elastomers and Compounds;382
29.1;A4.1 Processing of Styrenic Block Copolymers;382
29.2;A4.2 Processing of Polyolefin-based TPE (TPO);385
29.3;A4.3 Processing of Thermoplastic Vulcanizates (TPV);386
29.4;A4.4 Processing of Melt Processable Rubber (MPR);388
29.5;A4.5 Processing of Thermoplastic Polyurethanes (TPU);390
29.6;A4.6 Processing of Copolyester Thermoplastic Elastomers;392
29.7;A4.7 Processing of Polyamide Thermoplastic Elastomers (COPA);392
30;Appendix 5: Technical Data Sheets for Commercial
Thermoplastic Elastomers and Compounds;394
30.1;A5.1 SBC Data Sheets;394
30.2;A5.2 TPO Data Sheets;402
30.3;A5.3 TPV Data Sheets;407
30.4;A5.5 TPU Data Sheets;421
30.5;A5.6 COPE Data Sheets;427
30.6;A5.7 COPA Data Sheets;429
30.7;A5.8 Silicone TPE Data Sheets;433
30.8;A5.9 Other Specialty TPE Data Sheets;439
31;Appendix 6: Recent TPE Patents;442
32;Appendix 7: The 12 Principles of Green Chemistry
;444
33;Abbreviations and Acronyms;446
34;Glossary;448
35;Index;458

Leseproben

1

Introduction

Abstract

Thermoplastic elastomers are polymeric materials, which exhibit elasticity at ambient temperatures and can be processed as plastics by melt processing techniques. They are essentially two-phase systems. The phase separation is the result of limited compatibility of the two phases involved. When the material is heated above the melting point or melting range of the hard phase, its melt becomes homogeneous and can be shaped into desired shapes and/or products.

Keywords

Advantages and disadvantages of thermoplastic elastomersBlock copolymersClassification and nomenclature of thermoplastic elastomersCurrent demand for thermoplastic elastomersDynamic vulcanizationElasticityElastomersForecast of the growth of demand for thermoplastic elastomersPhase separationPhase structurePhysical thermoreversible cross-linksPolymerizationThermoplastic elastomers

Elasticity and Elastomers

Rubber-like materials consist of relatively long polymeric chains having a high degree of flexibility and mobility, joined into a network structure. The flexibility and mobility allow for a very high deformability. When subjected to external stresses, the long chains may alter their configuration rather rapidly because of the high chain mobility. When the chains are linked into a network structure, the system has solid-like features, where the chains are prevented from flowing relative to each other under external stresses. As a result, a typical rubber may be stretched up to 10 times its original length. On removal of the external forces, it rapidly recovers to its original dimensions, with essentially no residual or nonrecoverable strain.

When ordinary solids, such as crystalline or glassy materials, when subjected to external forces, the distance between two atoms may be altered by only a few angstroms for the deformation to be recoverable. At higher deformations, such materials either flow or fracture. The response of rubber is entirely intramolecular, that is, the externally applied forces are transmitted to the long chains through the linkages at their extremities, change their conformations, and each chain acts as an individual spring in response to the external forces [1].

High-molecular-weight polymers form entanglements by molecular intertwining (see Fig. 1.1(A)), with a spacing (in the bulk state) characteristic of the particular molecular structure. The spacing is expressed by molecular weight between entanglements (Me). Some examples of values of the molecular weight Me for several elastomers are in Table 1.1. Thus, a high-molecular-weight polymeric melt will show transient rubber-like behavior even in the absence of any permanent intermolecular bonds [2]. In a cross-linked elastomer, many of these entanglements are permanently locked in (see Fig. 1.1(B)), and at high enough degree of cross-linking, they may be regarded fully equivalent to cross-links, and as such they contribute to the elastic response of the material.

A network is obtained by linking of polymer chains together, and this linkage may be either chemical or physical. Physical linking can be obtained by [1]:

1. Absorption of chains onto the surface of finely divided particulate fillers

2. Formation of small crystallites

3. Coalescence of ionic centers

4. Coalescence of glassy blocks

These physical cross-links are, in general, not permanent and may disappear on swelling, or increase in temperature. Physical, thermoreversible networks are present in most thermoplastic elastomers (TPEs). Materials of this kind are very attractive technologically since they can be processed as thermoplastics, yet exhibit the behavior of rubber vulcanizates when cooled down to a sufficiently low temperature.

Figure 1.1(A) Molecular entanglements in a high-molecular-weight polymer. (B) Molecular entanglements locked by cross-linking.

Table 1.1

Representative Values of the Average Molecular Weight between Entanglements (Me) for Polymeric Meltsa

Polymer

Me

Polyethylene

4000

cis-1,4-Polybutadiene

7000

cis-1,4-Polyisoprene

14,000

Poly(isobutylene)

17,000

Poly(dimethyl siloxane)

29,000

Polystyrene

35,000

a Obtained from viscosity measurements.

Ref. [1].

Thermoplastic Elastomers

In the previous section, the concept of physical cross-links was introduced and a statement was made that materials with thermoreversible cross-links can be processed as thermoplastics (i.e., by melt processing) and that they exhibit elastic behavior similar to that of vulcanized (chemically cross-linked) conventional elastomers. Such materials represent a large group of polymers, called TPEs.

Phase Structure

Most TPEs are essentially phase-separated systems. The only currently known exceptions are Alcryn® (registered trademark of Advanced Polymer Alloys), a single-phase melt-processable rubber (MPR) and materials based on ionomers. Usually, one phase is hard and solid at ambient temperature and the other is an elastomer. Often, the phases are bonded chemically by block or graft polymerization. In other cases a fine dispersion of the phases is apparently sufficient [3]. The hard phase gives these TPEs their strength and represents the physical cross-links. Without it the elastomer phase would be free to flow under stress, and the polymer would be practically unusable. On the other hand, the elastomer phase provides flexibility and elasticity to the system. When the hard phase is melted or dissolved in a solvent, the material can flow and be processed by usual respective processing methods. Upon cooling or evaporation of the solvent, the hard phase solidifies and the material regains its strength and elasticity.

The individual polymers constituting the respective phases retain most of their characteristics so that each phase exhibits its specific glass transition temperature (Tg) or crystalline melting temperature (Tm). These two temperatures determine the points at which the particular elastomer goes through transitions in its physical properties. An example of this is in Fig. 1.2, which represents the measurement of flexural modulus over a wide range of temperatures. There are three distinct regions:

1. At very low temperatures, i.e., below the glass transition of the elastomeric phase, both phases are hard, so the material is stiff and brittle.

2. Above the Tg of the elastomeric phase the material softens and is elastic, resembling a conventional vulcanized rubber.

3. As the temperature increases, the modulus stays relatively constant (a region referred to as “rubbery plateau”) until the point where the hard phase softens or melts. At this point the material becomes a viscous fluid.

Figure 1.2Stiffness of typical thermoplastic elastomers in dependence on temperature.Courtesy: Hanser Publishers

Table 1.2

Glass Transition and Crystalline Melt Temperatures of Major TPEs

Styrenic block copolymers

S–B–S

?90

95 (Tg)

S–I–S

?60

95 (Tg)

S–EB–S

?55

95 (Tg) and 165 (Tm)a

Multiblock copolymers

Polyurethane elastomers

?40 to ?60

190 (Tm)

Polyester elastomers

?40

185 to 220 (Tm)

Polyamide elastomers

?40 to ?60

220 to 275 (Tm)

Polyethylene—poly(?-olefin)

?50

70 (Tm)

Poly(etherimide)—polysiloxane

?60

225 (Tg)

Hard polymer–elastomer combinations

Polypropylene—hydrocarbon rubberb

?60

165 (Tm)

Polypropylene—nitrile rubber

?40

165 (Tm)

PVC—(nitrile...