COMPATIBILITY OF THE COMPONENTS AND RELAX ATION PROCESSES IN POLYCARBONATE-POLY(BUTYLENE TEREPHTHALATE) BLENDS

Compatibility of the components and relaxation processes in polycarbon ate-poly(butylene terephthalate) blend were studied with the method of free torsional oscillation using an inverse torsion pendulum. It was found that at small blending times, the components of the blend were i ncompatible: the blend showed two glass transition temperatures, each related to the glass transition of each individual component. Increasi ng the blending time resulted in a decrease in dynamic modulus of the blend, in a decrease in the degree of crystallinity of the poly(butyle ne terephthalate) in the blend, and degeneration of the two glass tran sition temperatures of the components to a single glass transition tem perature. Increasing the blending temperature was found to have a simi lar effect. It was suggested that the properties of the blend were pre dominantly ruled by the reaction of interchain exchange, which is stro ngly controlled by the blending conditions.