engleski

Phase morphology comparison of polypropylene blends with different elastomers

Determination of the structure-property relationships of isotactic polypropylene blends with different elastomers demands complex investigation of phase structure, morphology, adhesion and mechanical properties. The comparison of phase morphology of isotactic polypropylene modified with styrenic rubber block copolymers (SEBS, SEBS-g-MA) and propylene-based metallocene copolymers (EPR-1, EPR-2) with elastomer content 0-20 vol% was performed by light microscopy, scanning electron microscopy (SEM) and transmision electron microscopy (TEM). Homogenously dispersed elastomer particles differed in size due to the difference in viscosity. The addition of different types of elastomers affected crystallization behaviour of polypropylene matrix and consequently morphology by competitive nucleation and solidification effects. As a result of these effects the difference in spherulite size between blends with different elastomers was revealed by polarization micrographs. It seems that the ethylene-propylene copolymers exibited some degree of miscibility or co-crystallizability with polypropylene in distinct to styrenic rubber block copolymers.

polypropylene ; elastomers ; phase morphology

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