Speciality Polymer Blends of Polybutylene Terephthalate and Glass-Filled Liquid Crystalline Polymer

Abstract

The blends of polybutylene terephthalate (PBT) with glass-filled thermotropic liquid crystalline polymer (LCP-g) was prepared by a melt mixing technique. The rheological, crystalline, thermal, dynamic mechanical, and morphological characteristics of these blends were investigated. The viscosity of the blends was higher than PBT in the whole shear rate range. At low shear rate, the viscosity of blends decreased with LCP concentration. Higher percent crystallinity was observed with increasing LCP-g content in the blend with PBT. The thermal stability increased with LCP-g content in the blend with PBT. The relaxation phenomenon as observed from DMTA analysis was changing depending on the blend ratio. The variation of stiffness and storage modulus as a function of LCP-g concentration at various temperatures suggested the phase inversion occurred at 40% LCP-g present in the blend. The orientation of the LCP-g molecules probably play a major role in determining the surface morphology rather than the surface free energy difference.