EVALUATION OF POLYESTERS AND THEIR BLENDS WITH BISPHENOL-A-POLYCARBONATE

A new polyester, poly(2-ethyl-2-methylpropylene terephthalate) (PEMPT), as well as poly(1,5-pentylene terephthalate), poly(1,7-heptylene terephthalate) and poly(1,9-nonylene terephthalate), have been synthesized and characterized with respect to specific criteria including phase behaviour studies with bisphenol-A-polycarbonate (PC). Binary blends of the four polyesters with PC (50/50 wt%) all exhibit two amorphous phases when an inhibitor is present to prevent transreactions. When prepared without inhibitor, the same blends are single phase, indicating that transreaction has occurred between blend components. Additionally, thermal analysis shows that PEMPT is amorphous and has improved thermal stability compared to the other aliphatic-aromatic polyesters studied. These characteristics are attributed to ethyl-methyl substitution of the propylene group in PEMPT.