Rheology and physical properties of ternary blends containing a thermotropic liquid crystalline copolyester

Ternary blends of polyarylate (PAR) U-Polymer 100, thermotropic liquid crystalline copolyester (LCP) Vectra A950, and a block copolyesterether Hytrel 7246 were investigated in terms of rheological properties, morphology, and mechanical properties. The PAR/Hytrel blend exhibited melting point depression and gave a unique single [T.sub.g] over the entire range of blend compositions. Addition of Hytrel to the PAR/LCP blend decreased both dynamic viscosity and storage modulus over the normal processing temperature range. Further, it notably reduced the voids between the LCP domains and the matrix, and improved the mechanical properties. The optimum usage level of Hytrel proved to be 2 phr.
INTRODUCTION Introducing an inorganic reinforcing fiber into an isotropic polymer is a common and important method of improving the mechanical properties of engineering plastics. However, this often brings about several [...]