Chemistry, Manufacture and Applications of Natural Rubber Related titles: Smart polymers and their applications (ISBN 978-0-85709-695-1) High temperature polymer blends (ISBN 978-1-84569-785-3) Natural fibre composites (ISBN 978-0-85709-524-4) Chemistry, Manufacture and Applications of Natural Rubber Edited by Shinzo Kohjiya and Yuko Ikeda amsterdam • boston • cambridge • heidelberg • london new york • oxford • paris • san diego san francisco • singapore • sydney • tokyo Woodhead Publishing is an imprint of Elsevier Woodhead Publishing is an imprint of Elsevier 80 High Street, Sawston, Cambridge, CB22 3HJ, UK 225 Wyman Street, Waltham, MA 02451, USA Langford Lane, Kidlington, OX5 1GB, UK Copyright © 2014 Woodhead Publishing Limited All rights reserved No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means electronic, mechanical, photocopying, recording or otherwise without the prior written permission of the publisher Permissions may be sought directly from Elsevier’s Science & Technology Rights Department in Oxford, UK: phone (+44) (0) 1865 843830; fax (+44) (0) 1865 853333; email: permissions@elsevier.com Alternatively you can submit your request online by visiting the Elsevier website at http://elsevier.com/locate/permissions, and selecting Obtaining permission to use Elsevier material Notice No responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein Because of rapid advances in the medical sciences, in particular, independent verification of diagnoses and drug dosages should be made British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library Library of Congress Control Number: 2013955853 ISBN 978-0-85709-683-8 (print) ISBN 978-0-85709-691-3 (online) For information on all Woodhead Publishing publications visit our website at http://store.elsevier.com/ Typeset by Replika Press Pvt Ltd, India Printed and bound in the United Kingdom This page intentionally left blank Contents Contributor contact details xiii Introduction xvii S Kohjiya, Kyoto University, Japan and Y Ikeda, Kyoto Institute of Technology, Japan Part I Properties and processing of natural rubber 1 Biosynthesis of natural rubber (NR) in different rubber-producing species K Cornish, The Ohio State University, USA 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 1.10 Introduction Rubber biosynthesis Rubber particles and rubber biosynthesis Kinetic analyses of rubber transferase Regulation of biosynthetic rate Regulation of molecular weight Identification and purification of rubber transferase Conclusions Acknowledgments References 10 12 13 19 23 24 25 25 Natural rubber (NR) biosynthesis: perspectives from polymer chemistry 30 J E Puskas and K Chiang, University of Akron, USA and B Barkakaty, Oak Ridge National Laboratory, USA, formerly of University of Akron, USA 2.1 2.2 2.3 2.4 2.5 Introduction Background on natural rubber (NR) Synthetic polyisoprenes (PIPs) Biosynthesis of NR In vitro biosynthesis of NR 30 31 36 41 47 vi Contents 2.6 2.7 2.8 2.9 NR in health care Future trends Acknowledgments References and further reading 51 54 57 57 Chemical modification of natural rubber (NR) for improved performance 68 P Phinyocheep, Mahidol University, Thailand 3.1 Introduction: The role of chemical modification in creating high-performance natural rubber (NR) The main types of chemical modification of NR Chemical modification by changing the structure or weight of rubber molecules Chemical modification of the carbon–carbon double bond Chemical modification by grafting molecules of a different polymer type Conclusions: Key issues in improving the properties of NR Future trends Sources of further information and advice References 104 106 108 110 Understanding network control by vulcanization for sulfur cross-linked natural rubber (NR) 119 Y Ikeda, Kyoto Institute of Technology, Japan 4.1 Introduction: The importance of sulfur cross-linking of rubber Using small-angle neutron scattering to analyze the network structure of sulfur cross-linked cis-1,4polyisoprene Network control in sulfur cross-linked cis-1,4polyisoprene Effect of network structure on strain-induced crystallization of sulfur cross-linked cis-1,4-polyisoprene Future trends: Key issues in improving the properties of natural rubber (NR) Acknowledgments References 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4.2 4.3 4.4 4.5 4.6 4.7 The effect of strain-induced crystallization (SIC) on the physical properties of natural rubber (NR) S Toki, National Metal and Materials Technology Center, Thailand 5.1 Introduction 68 70 71 80 95 119 122 126 127 131 131 132 135 135 Contents vii Temperature-induced crystallization (TIC) and straininduced crystallization (SIC) Stress relaxation and SIC Stress–strain relation and SIC Tear resistance and SIC Green strength and SIC Conclusions Acknowledgment References 136 137 144 154 158 162 163 163 Generating particulate silica fillers in situ to improve the mechanical properties of natural rubber (NR) 168 A Tohsan and Y Ikeda, Kyoto Institute of Technology, Japan 6.1 6.2 6.3 6.4 6.5 Introduction: Silica as a filler for rubber Particulate silica generated in situ Recent processes for adding filler to rubber Applications of in situ silica Conclusions: Key issues in improving the properties of natural rubber (NR) Future trends Acknowledgments References 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 6.6 6.7 6.8 Hydrophobic and hydrophilic silica-filled cross-linked natural rubber (NR): structure and properties A Kato, NISSAN ARC Ltd, Japan and Y Kokubo, R Tsushi and Y Ikeda, Kyoto Institute of Technology, Japan 7.1 Introduction: Silica reinforcement of natural rubber (NR) Testing hydrophobic and hydrophilic silica fillers: sample preparation Methods for analyzing silica filler behavior in crosslinked NR matrix Understanding the behavior of hydrophobic and hydrophilic silica fillers in cross-linked NR matrix Comparing hydrophobic and hydrophilic silica-filled cross-linked NR Conclusions Future trends Acknowledgments References 7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9 168 170 171 188 188 188 189 189 193 193 196 196 199 208 211 212 212 212 viii Contents Computer simulation of network formation in natural rubber (NR) T Nakao, The University of Tokyo, Japan, formerly of Sumitomo Bakelite Co Ltd, Japan and S Kohjiya, Kyoto University, Japan 8.1 8.2 Introduction Simulation methods for cold mastication of natural rubber (NR) Simulation methods for vulcanization of NR Summary Future trends Sources of further information and advice Acknowledgement References Appendix: Basic concept of cascade theory 8.3 8.4 8.5 8.6 8.7 8.8 8.9 Part II Applications of natural rubber Eco-friendly bio-composites using natural rubber (NR) matrices and natural fiber reinforcements A B Nair and R Joseph, Cochin University of Science and Technology, India 9.1 9.2 Introduction The importance of eco-friendly bio-composites from natural rubber (NR) Natural fiber reinforcement materials for NR biocomposites Factors influencing the effectiveness of fiber reinforcement Methods to improve the properties of NR bio-composites Physical properties of NR bio-composites Processing of NR bio-composites Applications of NR-based bio-composites with NR reinforcements Future trends Sources of further information and advice References 9.3 9.4 9.5 9.6 9.7 9.8 9.9 9.10 9.11 10 Natural rubber (NR) composites using cellulosic fiber reinforcements R C R Nunes, Universidade Federal Rio de Janeiro, Brazil 10.1 Introduction: The importance of natural rubber (NR)/cellulose composites 216 216 217 222 229 229 231 232 232 236 247 249 249 254 257 264 265 268 272 276 278 280 282 284 284 490 Index degradation of natural rubber by mastication at different rotor speeds, 218 influence of temperature on efficiency of mastication of natural rubber, 218 linen fibre, 268 liquid epoxidised deproteinised natural rubber (LDPNR), 89 liquid latex, 470 loop tack test, 355 Lorentz function, 123–4 lymphocytes, 454 maleated natural rubber (MNR), 271 maleinisation reaction, 95–8 ENE reaction of unsaturated enophile with double bond of NR, 98 proposed structure of attachment of maleic anhydride, 96 reaction of maleic anhydride with natural rubber via radical reaction, 97 marine products applications of calcium carbonate fillers, 319 effects on degradation of rubber composites, 315 effects on dynamic mechanical properties of rubber composites, 316–18 plots of storage modulus and tan of unified NR vulcanisates, 317 representative SEM micrographs of NR vulcanisates filled at 40 phr, 318 effects on mechanical properties of rubber composites, 309–15 optical micrographs of NR vulcanisate and 40phr commercial and 40 phr cuttlebone particles, 312 tear strength and DIN abrasion loss of unfilled NR vulcanisates, 314 typical formulation for rubber vulcanisation, in parts by weight per hundred parts, 309 unfilled NR vulcanisates or filled with either commercial or cuttlebone particles, 311 parameters affecting filler behaviour in rubber composites, 318–19 soft bio-composites from natural rubber (NR), 303–22 future trends, 320–1 process and materials for developing composites, 306–9 six representative marine crustaceans whose natural form or waste products, 305 utilised for their principal component as fillers, 304 Marketstrat, 54 Markov process, 236 mastication, 74, 217 matrix modification, 266, 267 maximum entropy method (MEM), 231 mechanical flexibility, 195 mechanical properties generating particulate silica fillers in situ of natural rubber (NR), 168–89 applications, 188 future trends, 188–9 particulate silica generated in situ, 170–1 recent processes for adding filler to rubber, 171–88 mechano-chemical milling, 418–19 mechano-chemical reaction, 217 mechanochemical methods rubber recycling, 412–19 elongation at break and tear strength as function of reclaim content, 416–17 properties of vulcanisates of virgin and revulcanised NR, 415 tensile properties of virgin NR vulcanisates and revulcanised NR reclaim, 412 variation of tensile strength and elongation at break, 420 mercaptobenzothiazole (MBT), 74 mesh size, 124–5 metallocene catalyst, 40 metathesis, 77 methyl methacrylate (MMA), 186–7 methylaluminoxane (MAO), 40 Michaelis–Menton plot, 12 microfibrils, 288 microscopic design technology, 344 microwave, 405–11 mill mixing, 272 Index Miller–Macosco network formation model, 226 Miscanthus, 260 mixing process, 307 Modified Lowry assay, 467 mohair, 264 molecular dynamics, 219–20, 227–8 molecular weight effect, 364–7 rubber, 19–23 Hill plot of incorporation of 14C-IPP, 21 molozonide, 78 moment analysis, 219 Monte Carlo equation, 209 Monte Carlo method, 219–20, 227–8 Mooney-Rivlin equation, 152–3 Mooney viscosity, 412 moving-die rheometry, 223 multi-scale design technology, 327 nanocrystalline cellulose, 277 National Institute for Occupational Safety and Health (NIOSH), 469–70 Natsyn, 40 natural fibre reinforcements eco-friendly bio-composites using natural rubber (NR) matrices, 249–81 applications, 276–7 factors influencing effectiveness, 264–5 future trends, 278–80 importance, 254–7 methods to improve properties, 265–7 physical properties, 268–72 processing, 272–6 sources of further information and advice, 280–1 materials for NR bio-composites, 257–64 animal fibres, 263–4 classification of fibres, 258 other fibres, 264 vegetable fibres, 258–63 natural living carbocationic polymerisation (NLCP), 45–7 ‘bio-inspired’ synthesis of cis-1,4polyisoprene, Plate V chain-growth polycondensation, 46 491 proposed mechanism of NR biosynthesis, Plate IV natural rubber (NR) background, 31–6 examples of rubber-producing plants, 33 history as raw material, 31–2 rubber-producing plants, 32–3 biosynthesis, 3–24, 41–7 annual global production and consumption (1900-2008), annual global production and consumption (1995-2012), biochemical pathway of in vivo biosynthesis, 41–5 biochemical representation of rubber biosynthesis, 44 identification and purification of rubber transferase, 23–4 kinetic analyses of rubber transferase, 12–13 mechanism of terpenoid biosynthesis, 45 natural living carbocationic polymerisation (NLCP), 45–7 polymer chemistry, 30–57 prenylation in short-chain isoprenoids, 45 regulation of biosynthetic rate, 13–19 regulation of molecular weight, 19–23 rubber biosynthesis, 6–10 rubber particles and biosynthesis, 10–12 characteristics for isolation and earthquake protection, 375–80 compression creep vs log time at various temperatures, 377 crack initiation time as function of ozone concentration for NR and EPDM, 379 frequency dependence of transmissibility as function of tan, 380 hydrostatic pressure gradient within a rubber layer sandwiched between metals, 377 linear load-displacement relation of NR-metal laminated bearing, 376 log compression creep rate vs log time, 378 492 Index shear stress vs fatigue life of NR for virgin sample and 70 years-aged sample, 379 chemical modification, 68–110 carbon–carbon double bond, 80–95 changing the structure and weight of rubber molecules, 71–80 future trends, 106–8 grafting molecules of a different polymer type, 95–104 key issues, 104–6 main types, 70–1 role in creating high-performance NR, 68–70 chemical structure, 33–6, Plate I building blocks, 34 13C NMR of Hevea and Guayule, 35 deproteinisation by treatment with 1–2% ethanol, 37 DL-limonene and isoprene, 33 computer simulation of network formation, 216–32 appendix and basic concept of cascade theory, 236–46 future trends, 229–31 simulation methods for cold mastication of NR, 217–22 simulation methods for vulcanisation of NR, 222–8 sources of further information and advice, 231–2 curing process, 337 examples of NR usage in demanding tyre applications, 343–9 aircraft tyres, 347–9 off-the-road tyres, 346–7 winter passenger car tyres, 343–6 forming process, 336–7 stress-strain curves for unvulcanised NR/IR blending 35 phr carbon black, 337 future trends, 54–7 biomimetic polymerisation of isoprene, 55–7 generating particulate silica fillers in situ to improve mechanical properties, 168–89 applications, 188 future trends, 188–9 recent processes for adding filler to rubber, 171–88 health care, 51–4 allergens from natural rubber latex, 53 in vitro biosynthesis, 47–51 detection of in vitro biosynthesis through SEC, 51 experimental MW results of in vitro NR systems for types of WRPs, 50 guayule NR biosynthesis, 49 SEC trace of endogenous NR from BF and in vitro NR rubber, 48 particulate silica generated in situ, 170–1 sol-gel process hydrolysis and condensation reactions of TEOS, 171 process and materials for developing composites, 306–9 background to NR composite fillers, 306–7 mixing process, 307 preparation of composite material, 308–9 processing of NR-based PSAs, 354 schematic diagram showing solution polymer method of processing PSAs, 354 properties required in tyre manufacture, 335–7 parts shaping process, 336 rubber mixing process, 335–6 properties required in tyre products, 337–43 control of tyre quality, 342–3 durability, 338–40 traction or braking and fuel efficiency, 340–2 quality standards for NR as raw material, 349–50 global standards for TSR ISO 2000, 350 recycling of synthetic isoprene rubbers, 395–429 approaches to reuse, 398–400 future trends, 427–8 reuse of NR, 400–5 soft bio-composites from marine products, 303–22 effects of fillers, 309–19 future trends, 320–1 Index strain-induced crystallisation (SIC) effect on physical properties, 135–63 green strength, 158–62 stress relaxation, 137–44 stress–strain relation, 144–54 tear resistance, 154–7 temperature-induced crystallisation (TIC) and SIC, 136–7 supply and demand in twenty-first century, 387–9 features of population movement in terms of annual income levels, 387 sustainable development improvement, 385–93 applications of state-of-the-art biotechnology, 391–2 biodiversity, 389–91 biosafety, 392 future trends, 392–3 synthetic polyisoprenes (PIPs), 36–41 tyre industry, 325–52 future trends, 350–2 types, manufacture and requirements, 326–35 usage for vibration isolation and earthquake protection of structures, 371–81 concept, 372–4 systems, 374–5 natural rubber (NR) composites cellulosic fibre reinforcements, 284–98 applications, 297–8 cellulose composites, 285–8 future trends, 298 natural cellulose nanocomposites, 288–90 regenerated cellulose nanocomposites, 290–7 natural rubber (NR) matrices eco-friendly bio-composites using natural fibre reinforcements, 249–81 applications, 276–7 factors influencing effectiveness, 264–5 future trends, 278–80 importance, 254–7 materials, 257–64 methods to improve properties, 265–7 493 physical properties, 268–72 processing, 272–6 sources of further information and advice, 280–1 natural rubber latex (NRL), 181–8 natural rubber latex (NRL) allergens types, 460–3 allergen in non-medical NRL products, 462 chemical allergens in NRL products, 462–3 glove allergens, 461–2 WHO/IUIS acknowledge NRL allergens, 461 natural rubber latex (NRL) allergy future trends, 471–2 acceleration of prevention programmes, 471 developments in rubber manufacture related to glove allergenicity, 471 molecular mechanisms of allergic sensitisation, diagnostics and therapeutic visions, 472 progress and extensions expected in standardisation work, 471 key issues in reducing allergy, 466–70 background, 466 mechanisms of development and clinical presentation, 457–64 allergic immune responses to NRL proteins, 458–9 background, historical aspects and evolution to an epidemic, 457–8 diagnosis, 460 glove powder, 463 latex-fruit syndrome, 463–4 types of allergens, 460–3 medical background, 453–6 basic concepts in immunology, 453–4 deviation of immune response towards allergic reactions, 454 genetic factors in type I allergies, 456 IgE-mediated allergies, 455–6 sensitisation in type I allergy, 454 type IV allergic reactions, 456 position papers, publications and guidelines, 474 suggested further information, 474 prevention practices, 468–70 alternative source materials for protective gloves, 470 494 Index banning usage of all NR products for healthcare, 470 education by physicians and administrators, 469 low allergen gloves usage for healthcare, 469 refraining from NRL gloves usage in non-medical work, 469–70 regulation of glove powder usage, 469 recent research, 452–74 sources of further information and advice, 473 recent review articles, 473–4 2005–2012, 473 recent trends in prevalence, 464–6 background, 464 decrease in new cases of type allergy, 464–5 developments in prevalence of type IV allergy, 465–6 risk factors, 459–60 main risk groups, 459 standardisation procedures, 466–8 international standards influencing monitoring and control, 467 network control sulfur cross-linked cis-1,4-polyisoprene, 126 schematic presentation of the formation of two-phase inhomogeneity in rubber vulcanizates, Plate VIII vulcanisation for sulfur cross-linked natural rubber (NR), 119–31 bis(dimethyldithiocarbamato) zinc(II)-mediated sulfur crosslinked formation and catalyst, 121 effect on strain-induced crystallisation of cis-1,4polyisoprene, 127–31 future trends and key issues in properties improvement, 131 reaction scheme for benzothiazolesulfenamideaccelerated, 120 small-angle neutron scattering usage to analyse network structure, 122–6 network formation computer simulation in natural rubber (NR), 216–32 appendix and basic concept of cascade theory, 236–46 simulation methods for cold mastication of NR, 217–22 simulation methods for vulcanisation of NR, 222–8 future trends, 229–31 schematic representation of portion of polymer network, 230 sources of further information and advice, 231–2 integrated simulation system OCTA for soft materials under seamless zooming, 232 neutron scattering, 131 neutron scattering analysis, 231 nickel 2-ethylhexanoate, 83 Nikon optical microscope, 198 Nipsil VN-3, 196 nitroxide-mediated free radical polymerization (NMP), 39 non-Gaussian chain model, 152 non-rubber components, 158 normalised crosslink density, 408–9 normalised gel fraction, 408–9 nuclear magnetic resonance spectroscopy, 131 occupational latex allergies, 469–70 off-the-road tyres, 346–7 illustration, 346 oil extended styrene butadiene rubber (OESBR), 91 Opinion by Scientific Committee on Medicinal Products and Medical Devices, 468 optical microscopic observation, 198 optical microscopy, 158 optical transparency, 200–2 dependence of total transmittance shield effect, diffuse transmittance and haze, 203 hydrophobic silica-filled NR films (NR-P-10RX, -30RX, -40RX and -80RX), 201 hydrophobic silica-filled NR films (NR-P-10VN, -30VN, -40VN and 80VN, 202 oscillating-disk, 223 oxidation process, 405 oxygen, 378–9 Index ozone, 78 ozonolysis, 78, 315 palladium, 83 Parthenium argentatum, 5, 7, 32, 34–5 binding constants and maximum reaction velocity of rubber transferase, particulate silica, 194 particulate silica fillers in situ to improve mechanical properties of natural rubber (NR), 168–89 applications, 188 future trends, 188–9 particulate silica generated in situ, 170–1 recent processes for adding filler to rubber, 171–88 schematic illustration of coupling reaction of TESPT in silica/rubber composite, 169 parts shaping process, 336 passenger car radial tyre (PCR), 329–30 path weighted function, 241–2 peel test, 356–7 schematic diagram of 90°, 180° and T-peel test, 357 peptisers, 335 peracetic acid, 88 perbenzoic acid, 87 performic acid, 88 periodic acid, 76 peroxycarboxylic acid, 87 petro resin, 363 phenylhydrazine, 75 physical properties strain-induced crystallisation (SIC) effect of natural rubber (NR), 135–63 green strength, 158–62 stress relaxation, 137–44 stress–strain relation, 144–54 tear resistance, 154–7 temperature-induced crystallisation (TIC) and SIC, 136–7 pineapple leaf, 269 plant fibres, 258 plastics, 141 polarity, 176–7 poly(ethylene-co-acrylic acid) (PEA), 92 polyhedral crystal, 137–9 polyisoprene (PIP), 34 polymer chemistry 495 natural rubber biosynthesis, 30–57 background, 31–6 biosynthesis, 41–7 future trends, 54–7 health care, 51–4 in vitro biosynthesis, 47–51 synthetic polyisoprenes (PIPs), 36–41 polymerisation, 18–19, 219 polystyrene, 100, 102 pond retting, 260–1 porphorbilinogen synthase (PBGS), 18 Post Industrial Revolution era, 393 potassium persulphate, 75 pre-mastication, 335 prenylation, 45 pressure sensitive adhesives (PSAs) epoxidised natural rubber application, 353–69 adhesive usage, 357–8 effect of coating thickness, 358–61 effect of molecular weight, 364–7 effect of tackifier and filler, 361–4 effect of testing rate, 367–8 future trends, 369 other factors affecting performance, 368 processing of NR and NR-based PSAs, 354 performance assessment, 354–7 adhesive tack, 354–5 peel test, 356–7 shear test, 355–6 pressure sensitive product (PSP), 355 probability generating function formalism and calculation, 238–42 branch pgf U expresses distribution of total number of offspring, 239 processing techniques, 272–6 calendering, 274–5 compression moulding, 272–3 rubber compound, 273 extrusion, 275–6 injection moulding, 274 rubber compound, 275 mill mixing, 272 reactive processing, 276 transfer moulding, 273–4 rubber compound, 274 propanal, 75 pulverisation methods, 400–3 NR vulcanisates, 400–3 496 Index properties of slabs of pulverised NR rubber waste, 403 schematic diagram of single screw extruder, 402 pyrolysis, 404–5 pyrolysis-gas chromatography, 421–1 qiviut, 264 quantum chemistry, 232 quarantine control, 392 radial construction, 346–7 radical reaction, 96 radioallergosorbent (RAST), 53 reactive processing, 276 real rubber, 150 recent research natural rubber latex (NRL) allergy, 452–74 future trends, 471–2 key issues in reducing allergy, 466–70 mechanisms of development and clinical presentation, 457–64 medical background, 453–6 recent trends in prevalence, 464–6 sources of further information and advice, 473 reclaiming agents, 399 recycling natural and synthetic isoprene rubbers, 395–429 approaches to reuse, 398–400 future trends, 427–8 reuse of NR, 400–5 natural rubber (NR), 405–21 chemical and biochemical techniques, 419–21 mechanochemical methods, 412–19 microwave and ultrasonic methods, 405–11 sulfur cross-linked natural rubber using supercritical carbon dioxide, 436–49 advantages of supercritical CO2 for devulcanisation, 438–9 devulcanisation in scCO2, 439–40 devulcanisation of carbon blackfilled, 440–2 devulcanisation of NR-based truck tire vulcanisate, 442–3 future trends, 449 role of scCO2 in devulcanisation, 443–8 synthetic isoprene rubber, 421–7 experimental and fitted values of normalised gel fraction, 426 normalised gel fraction as function of normalised crosslink density, 424 stress-strain curves for IR and NR vulcanisates and devulcanisates, 423 refiner techniques, 288 regenerated cellulose nanocomposites, 290–7 NR values, 295 stress at break of NR, 291 stress vs strain curves for natural rubber with carbon black, 297 tensile strength at break of NR/BR, 296 transmission electron microscopy of NR containing 15 phr of regenerated cellulose, 292 WAXD patterns of NR in 20 interval 2° to 40° at room temperature during uniaxial stretching, 294 relative crystallisation index (CRI), 129–30 renewable resource material (RRM), 412 resorcinol formaldehyde latex (RFL), 270, 287 retting flax, 260 reuse natural rubber (NR), 400–5 grinding and pulverisation methods for vulcanisates, 400–3 high-pressure high-temperature sintering method, 403–4 landfills and waste utilisation, 400 pyrolysis and usage as fuel source, 404–5 reverse Monte Carlo (RMC), 231 reversible addition-fragmentation chain transfer (RAFT), 39 ribbed smoke sheet (RSS), 349 rice husk ash (RHA), 271 rubber, 372–3 rubber biosynthesis, 6–10, 14 intramolecular lengths of different substances, regulation of biosynthetic rate, 13–19 allylic and non-allylic pyrophosphates, 13–14 Index allylic pyrophosphate isomers, 14–15 [14C] IPP incorporation by purified rubber particles, 14 initiator-dependent and independent polymerisation, 18–19 kinetic constants at various [Mg2+] for initiator-dependent reaction, 20 role of cofactor/activator, 16–18 time course of IPP incorporation by purified F elastica rubber particles, 20 time courses of substrate incorporation in H brasiliensis and P argentatum, 15–16 rubber particles, 10–12 SEM of rubber particles from H brasiliensis and P argentatum, 12 sum of neutral, phosphor and glycol lipids, 12 rubber composites, 306 rubber elasticity theory, 150 rubber elongation factor (REF), 461 rubber extrusion, 275–6 rubber industry, 449 rubber-metal laminated bearings, 375 rubber mixing process, 335–6 rubber network, 171–3 rubber technology, 195 rubber transferase, 7, 43 identification and purification, 23–4 kinetic analyses, 12–13 rubberised coir sheet, 277 run-flat technology, 332 sample preparation testing hydrophobic and hydrophilic silica fillers, 196 preparation, 197 scanning electron microscopy (SEM), 365–7 Scherrer equation, 152 scutching, 261 seismic isolation, 373 semi-efficient vulcanisation (SEV), 310 shaking capillary flow, 217 shear storage modulus, 440–1 shear strength, 361 shear test, 355–6 schematic diagram showing lap joint test, 356 short fibre reinforcements, 285–6 497 shoulder, 327 sidewall, 327–8 silane coupling agents, 193–4, 266–7 silanisation, 266 silica filler behaviour methods for analysing in cross-linked NR matrix conventional transmission electron microscopy (TEM) observation, 198 diffusion transmittance and haze measurement, 198 optical microscopic observation, 198 three-dimensional TEM (3D-TEM) measurements, 198–9 volume resistivity measurement, 196, 198 silica generated in situ NR latex, 181–8 chemical structures of four alkoxysilanes, 182 speculated formation mechanism of biphasic-structured composite, 185 stepwise SIC of cross-linking filled composite prepared by soft processing, 187 sulfur K-shell XANES spectra of sulfur cross-linked composites and sulfur cross-linked NR, 186 TEM photographs of uncross-linked and cross-linked composites, 184 temperature dependence of storage modulus of cross-linked and uncross composites, 187 swollen state of rubber network, 171–3 relationship between microscopic and macroscopic elongation ratios, 174 speculated morphological change by deformation for silica particles, 173 TEM photograph of in situ silica filled peroxide cross-linked IR nanocomposite, 172 variations of two-dimensional SAXS patterns by deformation for the in situ silica filled peroxide cross-linked IR nanocomposite, Plate IX 498 Index swollen state of uncross-linked natural rubber, 173–80 reconstructed mass density distribution of the silica inclusions for NR-mix-V and NR-in situ-V after removal of zinc compounds, Plate X speculated formation in TEOSswollen NR matrix by primary alkylamines, 178 stress-elongation curves of conventional silica VN-3 filled NR vulcanisates, 178 stress-strain behaviours at 25°C of conventional silica VN-3 and with and without silane, 176 structural parameters measured by 3D-TEM, 180 TEM image of conventional silica VN-3 and silica filled NR vulcanisates, 175 TEM image of conventional silica VN-3 filled NR vulcanisates, 177 synthetic rubber latex, 180–1 relationship between amount of in situ silica and mechanical properties, 181 silica loading, 196 silica reinforcement, 193–6 silk, 263 simulation methods cold mastication of NR, 217–22 hypothetical reasoning of cause of limit length, 220–2 kinetics, 219 limiting molecular chain length, 217–18 Monte Carlo method molecular dynamics, 219–20 vulcanisation of NR, 222–8 kinetics, 223–5 MC method and MD, 227–8 stochastic methods, 225–7 vulcanisate properties as function of cross-linking density, 222 sisal, 262 sisal fibre, 287 skin prick testing, 460 slip-link model, 152–3 small-angle neutron scattering, 122–6 usage to analyse network structure of sulfur cross-linked cis-1,4polyisoprene, 122–6 effect of cross-linking reagents on mesh size and size of network domain, 125 proposed models to explain the inhomogeneity of network structure in isoprene rubber vulcanizate, Plate VII recipes for preparation and properties of isoprene rubber vulcanizates, 123 small angle neutron scattering (SANS), 150 small angle X-ray scattering (SAXS), 136–7, 150 technique, 172–3 Smocluchowski-type reaction rate equation, 221 soaking time, 445 soft bio-composites natural rubber (NR) and marine products, 303–22 effects of fillers, 309–19 future trends, 320–1 process and materials for developing composites, 306–9 soft gel, 36 sol gel fraction, 414 sol-gel hydrolysis, 231 sol-gel process, 170 solid polymer electrolyte (SPE), 108 solution grinding, 401 solution polymer method, 354 South American leaf blight (SALB), 391–2 spina bifida, 465 standard Indonesian rubber (SIR), 349 standard Malaysian rubber (SMR), 349 standard Thai rubber (STR), 349 standardisation bodies, 473 standardisation procedures, 466–8 state-of-the-art biotechnology, 391–2 stochastic methods, 225–7 Scanian-case criterion for an elastically active network chain (EANC), 226 strain induced crystallisation (SIC), 85, 127, 136–7, 185–6 effect on physical properties of natural rubber (NR), 135–63 green strength, 158–62 Index stress relaxation, 137–44 stress–strain relation, 144–54 tear resistance, 154–7 temperature-induced crystallisation (TIC) and SIC, 136–7 network structure effect of sulfur crosslinked cis-1,4-polyisoprene, 127–31 relationship between CRI and vs shading of data points, 130 relationship between crystallinity index and stretching ratio of isoprene rubber, 129 relationship between onset strain of SIC, 130 tensile stress–strain curves of isoprene rubber vulcanizates, 128 stream retting, 261 stress-induced crystallisation, 409–10 stress relaxation, 137–44 experimental relations between decrease in volume, decrease in stress and time, 138 experimental relations between stress and time at –25°C, 138 normalised stress as function of temperature at strain 4.0 during constrained cooling, 140 normalised stress as function of temperature at strain 4.0 during constrained heating, 141 normalised stress during relaxation process and selected 2D WAXD patterns, 139 schematic model and role of crystallites during crystallisation, 143 time-dependent change of integrated intensity around 200 reflection in WAXD patterns, 144 time-dependent change of normalised tensile stress of NR and IR samples, 143 variation of force of vulcanised NR and variation of stress and crystallinity, 142 stress–strain curves, 409–10, 423 stress–strain relation, 144–54 hysteresis phenomena as shown by tension and birefringence in vulcanised NR, 145 499 maximum strain dependence of stress–strain relations at 20°C, 149 model of nucleation and crystallisation in vulcanised NR, 151 schematic model of stress decrease during extension between points, 149 schematic models of uniaxial deformed vulcanised polyisoprenes, 151 selected WAXD patterns collected during extension and retraction, 146 stress and crystallinity curves of NR during cyclic deformations at room temperature, 148 Treloar data on NR networks vs theoretical equations of dashed curved, 153 variations of crystal fraction and oriented amorphous fraction of NR, 147 styrene, 100, 101 substrate, 43 sulfur cross-linked natural rubber future trends, 449 total map of recycling of tire rubber, 449 network control by vulcanisation, 119–31 cis-1,4-polyisoprene, 126 effect on strain-induced crystallisation of cis-1,4polyisoprene, 127–31 future trends and key issues in properties improvement, 131 small-angle neutron scattering usage to analyse network structure, 122–6 recycling using supercritical carbon dioxide, 436–49 advantages of supercritical CO2 for devulcanisation, 438–9 devulcanisation in scCO2, 439–40 devulcanisation of carbon blackfilled, 440–2 devulcanisation of NR-based truck tire vulcanisate, 442–3 role of scCO2 in devulcanisation, 443–8 sulphonation reaction, 106–7 500 Index supercritical carbon dioxide recycling of sulfur cross-linked natural rubber, 436–49 advantages of supercritical CO2 for devulcanisation, 438–9 concept of devulcanisation process in sc CO2 for recycling NR products, 438 devulcanisation in scCO2, 439–40 devulcanisation of carbon blackfilled, 440–2 devulcanisation of NR-based truck tire vulcanisate, 442–3 future trends, 449 role of scCO2 in devulcanisation, 443–8 supercritical fluid, 438 supply risk management, 350–1 surface roughening, 287 sustainable development improvement natural rubber (NR), 385–93 13.6 billion years of events and environments surrounding us, 386 applications of state-of-the-art biotechnology, 391–2 biodiversity, 389–91 biosafety, 392 future trends, 392–3 supply and demand in twenty-first century, 387–9 swollen gels, 123–4 synchrotron scattering, 131 synchrotron X-ray, 144–5 synthetic composites, 264 synthetic isoprene rubbers recycling of natural rubber, 395–429 approaches to reuse, 398–400 future trends, 427–8 reuse of NR, 400–5 synthetic polyisoprenes (PIPs), 36–41 microstructures, 37, 38 nitroxide-mediated free radical polymerization (NMP) of IP, 39 synthetic rubber latex, 180–1 Synthetic Rubber Procurement Program, 31–2 tackifier, 361–4 Taraxacum kok-saghyz, 5, 32 tear resistance, 154–7 crystallinity near the crack tip as function of distance from origin, 157 deformed crystalline zones in NR sample, 156 schematic model of precut specimen of vulcanised NR after deforming monotonically, 155 tear strength, 157, 313 technically specified rubber (TSR), 349 temperature, 368 temperature-induced crystallisation (TIC), 136–7 tensile measurement, 172–3 tensile modulus, 270 tensile strength, 291, 410 tensile stress–strain curves, 127 terpenoids, 42–3 biosynthesis cycle, 43 testing rate effect, 367–8 tetrahydrofuran (TH F), 40 tetramethyl tin, 77 tetramethylthiuran disulfide (TMTD), 232 thermal pyrolysis, 421–1 three-chain model, 152–3 three-dimensional transmission electron microscopy (3D-TEM), 195, 198–9 observation, 204–8 CB aggregate network and its parameters, Plate XIII 3D-TEM images of hydrophobic silica-filled NR-P-10RX, -30RX, -40RX and -80RX, 206 3D-TEM images of hydrophobic silica-filled NR-P-10VN, -30VN, -40VN and -80VN, 207 dependence of closest distance between two nearest silica aggregates and STD, 208 hydrophilic silica network in NR (NR-P-10VN,-30VN, -40VN, and -80VN), Plate XII hydrophobic silica network in NR (NR-P-10RX,-30RX, -40RX, and -80RX), Plate XI three-electrode method, 196 3-(methacryloyloxy) propyltris(methylsiloxy) silane (MPTS), 102 Index time-temperature superposition theory (TTS), 341 toluenesulphonyl- hydrazide (TSH), 84 traditional calendar mill method, 354 transfer moulding, 273–4 transmission electron microscopy (TEM), 194–5, 198, 202–4, 291–2 observation, 202–4 conventional TEM images of hydrophobic silica-filled NR-P10RX,-30RX, -40RX and -80RX, 204 conventional TEM images of hydrophobic silica-filled NR-P10VN,-30VN, -40VN and -80VN, 205 transprenyltransferases, 43 tread, 327 tread pattern design, 343–4 tree decomposition, 242 tree-like model, 236–8 number of offspring and probability for zero-generation and firstgeneration unit, 238 procedure of polyfunctional polymerisation, 237 regards a polymer as genealogical tree, 237 tree-like structure, 236 Treolar’s data, 152–3 triisobutylaluminum, 83 2-azo-bisisobutyronitrile (ABIN), 39 diazo-3-trifluoropropionyloxy geranyl pyrophosphate (DATFP-GPP), 49–50 2-ethylsulfanylthiocarbonylsulfanylpropionic acid ethyl ester (ETS PE), 39 2-hydroxyethyl methacrylate (HEMA), 102 2,4,6-triisopropylbenzenesulfonylhydrazide (TPSH), 85 2,4,6-trimethyl benzenesulfonylhydrazide (MSH), 85 truck and bus radial tyre (TBR), 329–30 tungsten hexachloride, 77 type I allergy sensitisation, 454 type I (immediate hypersensitivity) reactions, 458 symptoms of IgE-mediated NRL allergy, 459 501 type II (delayed hypersensitivity) reactions, 458–9 type IV allergic reactions, 456 tyre development process, 340 tyre failure, 338 tyre industry natural rubber (NR), 325–52 examples of NR usage in demanding tyre applications, 343–9 future trends, 350–2 NR properties required in tyre manufacture, 335–7 NR properties required in tyre products, 337–43 quality standards for NR as raw material, 349–50 types, manufacture and requirements, 326–35 tyres, 326–35 anatomy and construction and materials, 326–30 basic construction of typical tyre, 328 microscopic-macroscopic composites, 327 NR ratio in all rubber components for tyre usage in Japan, 330 typical weight composition, 330 weight composition, 329 basic functions and desired performances, 332 environmental aspects, 333–5 desired performance of tyres, 333 GHG emission factors of NR and SR, 334 GHG emissions in life cycle of passenger car tyre, 333 retread, 334 manufacturing process, 330–2 production process for passenger car radial tyre, 331 types, 326 illustration, 326 ultrasonic devulcanisation, 406–7, 422–3 ultrasonic irradiation, 217, 406 ultrasonic methods, 405–11 normalised gel fraction vs normalised crosslink density for various rubbers, 408 stress-strain curves of virgin rubbers and revulcanised rubbers, 409 502 Index tensile strength, elongation at break and modulus at 100% of devulcanised NR, 411 ultrasound power consumption vs amplitude for various rubbers during devulcanisation, 407 ultrasonic power consumption, 407–8 ultraviolet (UV) radiation, 255 uncross-linked natural rubber, 173–80 uni-axial stretching, 154 Universal Precautions, 457–8 vacuum pyrolysis, 405 van der Waals forces, 193 van der Waals theory, 153 vegetable fibres, 258–63 classification of natural fibres, 258 vibration isolation concept, 372–4 response spectra for various earthquake waves, 373 vibration of simple linear viscoelastic system, 372 natural rubber (NR) usage for earthquake protection of structures, 371–81 characteristics, 375–80 systems, 374–5 violent stirring, 217 viscoelastic energy dissipation, 341 volume resistivity, 199–200 dependence at room temperature on silica loading of hydrophilic and hydrophobic NR, 199 measurement, 196 vulcanisation, 222–8 network control for sulfur cross-linked natural rubber (NR), 119–31 cis-1,4-polyisoprene, 126 effect on strain-induced crystallisation of cis-1,4polyisoprene, 127–31 future trends and key issues in properties improvement, 131 small-angle neutron scattering usage to analyse network structure, 122–6 NR kinetics, 223–5 conventional vs semi-effective vs effective vulcanisation systems, 224 reaction pathway of benzothiazole sulphonamide accelerated vulcanisation, 225 rheometer chart of accelerated sulphur vulcanisation process, 223 vulcanisation process, 376 vulcanised rubber, 152 washed rubber particles (WRP), 47, 49 waste utilisation, 400 water solubility, 176–7 weaving, 256 wet grinding, 401 wide-angle X-ray diffraction (WAXD), 127, 136–7, 185–6 winter passenger car tyres, 343–6 benefit of morphological control to improve trade-offs between ice grip and dry handling, 345 complex three-dimensional shape, 344 foamed rubber, 345 morphological controls of NR/BR blend system, Plate XVI wool, 263 World Commission on Environment and Development (WCED), 385 World Health Organisation (WHO), 460–1 X-ray, 231, 293 X-ray absorption fine structure spectroscopy, 131 X-ray absorption near edge structure (XANES), 169, 185 X-ray diffraction, 137, 279 X-ray irradiation, 127 X-ray photoelectron spectroscopy, 169–70 Young’s modulus, 375, 413 Ziegler–Natta catalyst, 40 zinc oxide, 125 This page intentionally left blank This page intentionally left blank ... Part II Applications of natural rubber Eco-friendly bio-composites using natural rubber (NR) matrices and natural fiber reinforcements A B Nair and R Joseph, Cochin University of Science and Technology,... Recycling of natural and synthetic isoprene rubbers A I Isayev, University of Akron, USA 16.1 16.2 Introduction Approaches to the reuse and recycling of natural rubber (NR) Reuse of NR Recycling of. .. Processing of natural rubber (NR) and NR-based PSAs Assessing the performance of a PSA The use of epoxidized NR as an adhesive Effect of coating thickness Effect of tackifier and filler Effect of molecular