Synthesis and characterization of new cardo polyesters

New phthalide-containing bisphenols, phenolphthalein-N-(3-methylanilide) (3-PMA), and phenolphthalein-N-(4-methylanilide) (4-PMA), were synthesized from phenolphthalein and m- and p-toluidines. These bisphenols were polycondensed with terephthaloyl chloride (TPC) using an interfacial or solution polymerization technique to yield new polyesters. Copolymers were also obtained by utilizing different molar proportion of phenolphthalein (PPH) and 3-PMA or 4-PMA with TPC. The polymers prepared by solution polymerization were obtained in 93-99% yields and showed reduced viscosities in the range 0.37-0.83 dL/g. They were readily soluble in chlorinated hydrocarbons and aprotic polar solvents. The polyesters showed glass transition temperatures in the range 261-300 degrees C as measured by DSC. Thermogravimetric analysis of the polyesters indicated no weight loss below 408 degrees C under N-2 atmosphere. Structure-property correlations among these cardo polyesters have been discussed. (C) 1997 John Wiley & Sons, Inc.