Poly(phenylene sulfide)/liquid crystalline polymer blends .1. Non-isothermal crystallization kinetics

The non-isothermal crystallization behaviour of poly(phenylene sulfide) (PPS) in blends with thermotropic liquid crystalline polymer (TLCP) was studied by means of differential scanning calorimetry. The TLCP chosen for the investigation was poly(oxybenzoate-co-ethylene terephthalate). It was observed that the Ozawa equation is valid not only for neat PPS, but also for the blends. The PPS crystallization temperature was found to increase markedly upon addition of the TLCP. A notable reduction in Avrami exponents for the PPS/LCP blend systems suggests that the nucleated process leads to rod-shaped growth with thermal nucleation. The cooling crystallization function, which represents the rate of non-isothermal crystallization, was found to decrease with decreasing temperature and/or increase in LCP content. It has been concluded that the non-isothermal crystallization of PPS is strongly accelerated by the presence of TLCP. (C) 1997 Elsevier Science Ltd.