BLENDS OF POLYOLEFINS AND SEMIFLEXIBLE LIQUID-CRYSTALLINE POLYESTERS .1. THERMOGRAVIMETRIC ANALYSIS

The thermal stability of blends consisting of polyethylene (PE) or iso tactic polypropylene (PP) with two different semiflexible liquid cryst alline polyesters (LCP) was analysed by thermogravimetry (TG) under ni trogen and air atmospheres. The effects of the structural parameters o f the LCP and of its content in the blends were evaluated. The tempera tures at which degradation starts indicated that the stability of the mixtures is governed by the presence of the less stable component, und er the experimental conditions applied. Comparison between predicted a nd experimental weight losses versus temperature support speculations on polymer-polymer interactions in the blends.