Dielectric properties of phase separated polymer solids: 1. Styrene-butadiene-styrene triblock copolymers
1978; Elsevier BV; Volume: 19; Issue: 8 Linguagem: Inglês
10.1016/0032-3861(78)90198-2
ISSN1873-2291
AutoresA. M. North, Richard A. Pethrick, Alex Wilson,
Tópico(s)Polymer crystallization and properties
ResumoTheories currently applicable to the description of the low frequency dielectric loss, associated with trapping of charge carriers at interphase boundaries in polymers, are presented. Experimental observations on styrene-butadiene-styrene triblock copolymers are compared with theory. The interfacial polarization process in a film-cast copolymer with 30 wt % styrene was found to be in reasonable agreement with predictions for a morphology of parallel cylinders oriented at random, whereas that for a 50 wt % styrene copolymer was compatible with prediction for a random arrangement of partly parallel lamellae. These structures correspond to morphologies observed by electron microscopic observation. No evidence was found for a dielectric effect specifically requiring a diffuse conducting interfacial zone between the polystyrene and polybutadiene domains. The bulk d.c. conductivity also correlated with predictions made using the same parameters as those involved in calculation of the relaxation effects.
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