Reactive Processing Of Polymer Blend Using Reactive Compatibilization And Dynamic Crosslinking: Phase Morphology Control And Microstructure – Property Relations

This chapter covers the area of polymer blends produced via melt-processing. The blends are first introduced based on their miscible or immiscible nature. Advantages and disadvantages of one class over the other are briefly highlighted. The need to compatibilize immiscible polymer blends is emphasized. The two main strategies of compatibilization, i.e., physical blending which consists of adding a pre-formed copolymer to compatibilize the blend and reactive blending which is based on the in-situ generation of the compatibilizing agent, are compared. The key-factors such as viscosity ratio, blend composition, interfacial tension and mixing conditions that control the phase morphology in immiscible blends are discussed in detail. A large section is devoted to the discussion of compatibilization with extensive consideration of all aspects of the reactive compatibilization approach. Moreover, in-situ copolymer formation and compatibilization activity are discussed in terms of the effect of : - the miscibility of the compatibilizer precursor, - the configuration of reactive end groups and, - the content of reactive groups. In the last section, the thermoplastic vulcanizates which are a particular case of polymer blends are described in terms of their composition, their phase morphology development and their specific elasticity and recovery behaviour.

Key words: Polymer blends, reactive processing, compatibilization, phase morphology, dynamic vulcanization