Steady-state rheological behaviour and morphology of poly(ethylene terephthalate) liquid crystalline polymer blends.

The rheological-behaviour of injection molded blends of polyethylene terephthalate, PET, with a liquid crystalline polymer,LCP, Vectra A950, from Hoechst, was analyzed using a controlled strain rheometer, ARES and a controlled tension rheometer, SR-200, both from Rheometrics, in a paralell plate geometry. Also capillar rheometry was used. PET/LCP blends in a weight percent ratio of 80/20, 60/40 40/60 and 20/80 were studied. It was observed that above 10 s(-1), the addition of the LCP resulted in a decrease of the viscosity values. In all the blends, it was also observed an increase in the melt elasticity above 10 s(-1). The dynamic rheological properties increased with the increase in LCP; up to the 60/40 ratio the creep recovery increased The usual skin-core morphology was observed by scanning electron microscopy.