Reactive Modifiers for Polymers

Chemical modification of polymers by reactive modifiers is no longer an academic curiosity but a commercial reality that has delivered a diverse range of speciality materials for niche markets: reactively grafted styrenic alloys, maleated polyolefins, super-tough nylons, silane modified and moisture-cured polyolefins, and thermoplastic elastomers, are but few exam­ ples of commercial successes. Although the approach of reactive modification of polymers has been largely achieved either in solution or in the solid state (through in situ reactions in polymer melts), it is the latter route that has attracted most attention in the last two decades owing to its flexibility and cost-effective­ ness. This route, referred to as reactive processing, focuses on the use of suitable reactive modifier(s) and the adoption of conventional polymer processing machinery, an extruder or a mixer, as a chemical reactor, to perform in situ targeted reactions for chemical modification of preformed polymers. This relatively simple, though scientifically highly challenging, approach to reactive modification offers unique opportunities in exploiting various reactive modifiers for the purpose of altering and transforming in a controlled manner the properties of preformed commercial polymers into new/speciality materials with tailor-made properties and custom-designed performance for target applications. Such an economically attractive route constitutes a radical diversion away from the traditional practices of manufacturing new polymers from monomers which involves massive in­ vestments in sophisticated technologies and chemical plants.

Table of Contents:
1 Free-radical grafting of monomers onto polymers by reactive extrusion: principles and applications.- 1.1 Introduction.- 1.2 Free-radical grafting: an overall mechanistic view.- 1.3 Melt free-radical grafting: particular features.- 1.4 Challenges facing melt free-radical grafting.- 1.5 Recent advances in melt free-radical grafting.- 1.6 Concluding remarks.- Appendix l.A.- References.- 2 Modification of polypropylene by organic peroxides.- 2.1 Introduction.- 2.2 Background.- 2.3 Modifications of PP by organic peroxides.- 2.4 Future trends.- Acknowledgements.- Appendix 2.A.- 2.A.1 List of abbreviations.- References.- 3 Blends of polyamides and maleic-anhydride- containing polymers: interfacial chemistry and properties.- 3.1 Introduction.- 3.2 Interdependence of chemistry, rheology and morphology-interface.- 3.3 Relationships between morphology-interface and blend properties.- 3.4 Overall model and future trends.- Appendix 3.A.- 3.A.1 List of abbreviations.- References.- 4 Modification of polymer melts by oxazolines and their use for interfacial coupling reactions with other functional polymers.- 4.1 Introduction.- 4.2 Preparation of oxazoline-functionalized polymers.- 4.3 Interfacial reactions with other functional polymers.- 4.4 Modification of polymer melts by bis-2-oxazolines.- 4.5 Conclusions.- 4.6 Future trends.- Appendix 4.A.- 4.A.1 List of abbreviations.- References.- 5 Moisture cross-linkable silane-modified polyolefins.- 5.1 Introduction.- 5.2 Processes for cross-linking polyolefins.- 5.3 The chemistry of silane cross-linking.- 5.4 Silane-grafting processes.- 5.5 Silane copolymerisation processes.- 5.6 Structure and general properties of silane cross-linked polyolefins.- 5.7 Applications of silane cross-linked polyolefins.- 5.8 Other silane cross-linking approaches.- 5.9 Concluding remarks and future trends.- Appendix 5.A.- 5.A.1 List of abbreviations.- References.- 6 Reactive antioxidants for polymers.- 6.1 Introduction.- 6.2 Antioxidants and polymer oxidation: a mechanistic overview.- 6.3 Effect of chemical structure and physical factors on antioxidant performance.- 6.4 Reactive antioxidants and routes to antioxidant permanency in polymers.- 6.5 Concluding remarks.- Appendix 6.A.- 6.A.1 Abbreviations.- References.- 7 Synthesis of poly olefin graft and block copolymers by reactive borane reagents and applications in polyolefin trends and composites.- 7.1 Introduction.- 7.2 Synthesis of borane-functionalized olefinic polymers.- 7.3 Utilization of borane-functionalized polymers in graft and block copolymer formation.- 7.4 The use of graft and block copolymers prepared via borane- functionalized polymer intermediates in the compatibilization of polymer blends.- 7.5 Conclusions and future trends.- Acknowledgement.- Appendix 7.A.- 7.A.1 List of abbreviations.- References.- 8 Electron beam radiation graft modification of preformed polymer architecture.- 8.1 Introduction.- 8.2 Principles of pre-irradiation electron-beam grafting in inert atmosphere.- 8.3 Parameters affecting electron-beam grafting.- 8.4 Different polymer architectures suitable for electron-beam grafting.- 8.5 Applications of electron-beam grafting.- 8.6 Concluding remarks.- Appendix 8.A.- 8.A.1 List of abbreviations.- References.- 9 Thermoplastic elastomers based on elastomer/thermoplastic blends dynamically vulcanized.- 9.1 Introduction.- 9.2 The preparation of elastomer/plastic blends by dynamic vulcanization.- 9.3 Properties of blends prepared by dynamic vulcanization.- 9.4 Technological applications.- Appendix 9.A.- 9.A.1 Abbreviations.- References.