Synthesis of aromatic polyester (polyarylate) by removal of phenol from condensation polymerization of bisphenol A and diphenyl terephthalate isophthalate mixtures

Industrially available poly(bisphenol A arenedicarboxylate) (polyarylate) i s conventionally produced by the interfacial condensation polymerization of bisphenol A and the mixture of terephthaloyl/isophthaloyl chlorides. We no w report a new synthetic method without using the acid chloride derivatives , and the synthesis of oligomeric arenedicarboxylate by the melt condensati on polymerization of bisphenol A and diphenyl terephthalate/isophthalate (m ole ratio of reactants is 1/0.5/0.5). By removal of phenol from the reactio n mixture, we obtained oligomeric ester, which can be changed to a high mol ecular weight polyester in the subsequent reactions. This report discussed the kinetics of the melt condensation of bisphenol A and diphenyl terephtha late/isophthalate mixtures. The melt condensation polymerization of bisphen ol A and diphenyl terephthalate/isophthalate was analyzed by the bimolecula r reaction of -OH and a phenyl ester. The activation energy was estimated t o be 32.2 kcal/mol. The relationships between the reduced viscosity and mol ecular weight was estimated and the following experimental equation was obt ained; eta(sp)/C=7.46 x 10(-5) (M) over bar(w)(0.83). Polymer was analyzed by H-1-NMR, and the ratio of the end group of the hydroxy group to phenyl e ster group was determined. FD-MS suggest ed four types of oligomeric ester end groups: phenyl-phenyl, phenyl-hydroxy, hydroxy-hydroxy, and cyclic.