Optical properties elastomeric networks

BirGfring6nC6 of Polymer Networks. Elastomeric polymer networks deserve special mention because their cross-linked structure gives them unique physical properties, unlike those of other polymers. Covalently bonded networks are insoluble in any solvent, even in those that dissolve their precursor polymers. Optical techniques such as strain-induced birefringence allow the development of structure-property relationships as well as the study of their optical properties. Here we review some of the classical theories as well as some of the latest developments in the field. 

In this section, we present the morphology development of neat elastomeric polypropylene as well as its blend with POE by means of optical microscopy and atomic force microscopy. ePP is essentially atactic polypropylene, which is amorphous in character, but contains some level of isotacticity (26). The incorporation of crystal-lizable iPP blocks provides the physical junctions to these amorphous ePP to possess elastomeric properties like a network in the solid state, but these crystal junctions can be removed upon melting, and thus affords melt processability like thermoplastics. 

Elastomeric LCP networks with the potential to show piezoelectric behavior were described by Zentel and co-workers [109, 110, 125, 773]. More recently, Meier and Finkelmann [774, 775] created piezoelectric cholesteric elastomers and described some of their properties. Polymers [776] and networks [126,777] with nonlinear optical responses were recently synthesized. Some of these polymers are liquid crystalline [776], We see no reason why mesogenic monomers and NLO responsive monomers may not soon be combined to form permanently crosslinked NLO LCP networks. 

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