BLENDS OF A THERMOTROPIC LCP AND A THERMOPLASTIC ELASTOMER .2. FORMATION AND STABILITY OF LCP FIBERS

The formation of fibers during blending of a thermotropic liquid crystalline polymer (LCP) with a thermoplastic elastomer (TPE) using shear flow, and the stability of the fibers and the blend morphologies at elevated temperatures were studied. The polymers used were Vectra A900 (LCP) and Kraton G1650 (TPE). Fiber formation in (predominantly) shear flow was studied using a single screw extruder of which the die was removed. Fibers were obtained in blends with 5 vol% LCP at shear rates as low as 6.3 s-1. Conventional extrusion through a die was used for preparing materials for the studies of the thermal stability of blends and isolated fibers-isolated LCP-fibers surrounded by a TPE-matrix disintegrate when held above the melting point of the LCP. Annealing of the blends at this melting temperature results in changes of the morphology and in a fairly rapid decrease of the modulus of elasticity.