EFFECT OF CHEMICAL-STRUCTURE ON CRYSTALLIZATION BEHAVIOR OF POLY(PHENYLENE ALKYLENE DICARBOXYLATE) (PPAD)

Various poly(p-phenylene alkylene dicarboxylates) (PPADs) were synthes ized and their crystallization behavior was examined as functions of t he length and the odd/even numbers of carbon atoms in the aliphatic co mponent. PPADs with longer aliphatic units of even-numbered carbon ato ms were found to crystallize faster than do those of other cases. The results are compared with the crystallization behavior of conventional poly( alkylene terephthalate)s(PATs), e.g., poly(ethylene terephthala te) (PET) and poly(butylene terephthalate) (PET), which have the same chemical composition as the corresponding PPAD but the reversed direct ion of the ester group. The effects of this structural difference on t he melting temperature and the crystallization kinetics are also discu ssed. (C) 1997 John Wiley & Sons, Inc.