CROSSLINKING BY ETHERIFICATION OF BISEPOXIDE WITH ADDUCTS OF DIVALENT METAL SALTS OF P-AMINOBENZOIC ACID AND ANHYDRIDE

摘要

Crosslinking by etherification of a large excess of bisepoxide with adducts of divalent metal salts of p-aminobenzoic acid and dicarboxylic acid anhydride was investigated. As the divalent metals, Mg and Ca were selected and hexahydrophthalic anhydride was the anhydride used. As the bisepoxide, bisphenol A diglycidyl ether was used. In the crosslinking reactions, the metal carboxylate groups showed catalytic action and the Ca carboxylate group showed higher catalytic activity than did the Mg carboxylate group. Therefore, the crosslinking reactions were supposed to proceed via an ionic mechanism in which the carboxylate anion is concerned. As for the physical and other properties of the metal-containing cured resins, the T-g determined by dynamic mechanical properties increased with increase in the metal content. Also, the heat-distortion temperature increased with increase in the metal content. Interestingly, the cured resins showed very high impact strength and the strength increased markedly with decrease in the T-g. Scanning electron micrographs for fracture surfaces of the cured resins with high impact strength showed uneven patterns, which suggests microphase separation. From TGA and DTA, it was suggested that the metal carboxylate groups accelerated thermal decomposition. In addition, the cured resins exhibited high boiling water and water resistances. (C) 1996 John Wiley & Sons, Inc. [References: 10]