BLENDS OF AMIDE-MODIFIED POLYBUTYLENE TEREPHTHALATE AND POLYCARBONATE

摘要

Blends of amide-modified polybutylene terephthalate (PBTA) with polycarbonate (PC) were investigated. The focus of the study was to determine differences between blends produced from PBTAs comprised of hexanediamide units (PBTA-6) vs. butanediamide units (PBTA-4). The thermal properties of neat PBTA-4 and neat PBTA-6 were found to be vastly different. For PBTA-4, observed melting temperature increased with increasing diamide content, while PBTA-6 showed a decrease in observed melting point with increasing diamide content. In addition, at a diamide content of 5.0 mole percent, the crystallization rate of PBTA-4 was found to be higher than that of unmodified polybutylene terephthalate (PBT); while PBTA-6 crystallized slower than PBT. With regard to blends with PC, both PBTA-4 and PBTA-6 showed less partial miscibility with PC than PBT with PC. The impact and mechanical properties of the PC/PBTA blends were similar to PC/PBT blends. At low undercoolings, the inherently higher nucleation density of the PBTAs was found to result in more complete crystallization of blends possessing a PC continuous phase.