BLENDS OF A PPO-PS ALLOY WITH A LIQUID-CRYSTALLINE POLYMER

Blends of a PPO-PS alloy with a liquid crystalline polymer have been s tudied for their dynamic properties, theology, mechanical properties, and morphology. This work is an extension of our previous work on PPO/ LCP blends. The addition of the LCP to the PPO-PS alloy resulted in a marked reduction in the viscosity of the blends and increased processi bility. The dynamic studies showed that the alloy is immiscible and in compatible with the LCP at all concentrations. The tensile properties of the blends showed a drastic increase with the increase in LCP conce ntration, thus indicating that the LCP acted as a reinforcing agent. T he tensile strength, secant modulus, and impact strength of the PPO-PS /LCP blends were significantly higher than that of PPO/LCP blends. Mor phology of the injection molded samples of the PPO-PS/LCP blends showe d that the in situ formed fibrous LCP phase was preserved in the solid ified form. A distinct skin-core morphology was also seen for the blen ds, particularly with low LCP concentrations. The improvement of the m echanical properties of the blends is attributed to these in situ fibe rs of LCP embedded in the PPO-PS matrix. The improvement in the proper ties of PPO-PS/LCP over PPO/LCP is also attributed to the addition of the PS which consolidates the matrix. (C) 1995 John Wiley and Sons, In c.