Mechanical and viscoelastic properties of extruded sheets from blends containing liquid crystalline copolyesters and polycarbonate
Abstract:Sheets from blends containing liquid crystalline polymer (LCP) and bisphenol-A polycarbonate (PC) were prepared using a twin screw extruder at various take-up speeds. Thermal behavior, mechanical properties, and viscoelastic properties of sheets with various compositions were investigated using differential scanning calorimetry (DSC), dynamic mechanical analysis measurement (DMTA), and sonic velocity measurement. DMTA studies showed the blends to have two glass transition temperatures (Tg) corresponding to those of the PC-rich and LCP-rich phases. Blends of PC and LCP were immiscible, although their Tgs varied slightly with composition. The dynamic and sonic moduli increased with increasing LCP content owing to the high modulus of LCP. The modulus remained unchanged with increasing LCP content at low LCP wt% (<20 wt% LCP).
Document Type: Research Article
Affiliations: National Institute of Materials and Chemical Research, Tsukuba, Ibaraki 305-8565, Japan
Publication date: January 1, 1999