Elastomers polycarbonates, elastomeric

The properties of elastomeric materials are also greatly iafluenced by the presence of strong interchain, ie, iatermolecular, forces which can result ia the formation of crystalline domains. Thus the elastomeric properties are those of an amorphous material having weak interchain iateractions and hence no crystallisation. At the other extreme of polymer properties are fiber-forming polymers, such as nylon, which when properly oriented lead to the formation of permanent, crystalline fibers. In between these two extremes is a whole range of polymers, from purely amorphous elastomers to partially crystalline plastics, such as polyethylene, polypropylene, polycarbonates, etc. 

Blends of polycarbonate and elastomers contain mostly graft copolymers based on butadiene and acrylate rubbers as the elastomeric component Polycarbonate blends with special thermoplastic elastomers, e.g., styrene/ethylene/butylene/styrene block copolymers (SEES) are another interesting product class. These blends exhibit improved resistance to gasoUne compared to polycarbonate, Figure 5.309. 

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