Synthesis and Characterization of Polyamide by Interfacial Polycondensation of Dichloroformyl-Containing γ-Lactone with Hexamethylenediamine

Abstract(2R*,4S*)-4-chloroformyl-2-chloroformylmethyl-2,4-dimethyl-4-butanolide was prepared by the chemical transformation of t-butyl methacrylate dimer telomerized using bromotrichloromethane. The interfacial polycondensation of this acid dichloride with hexamethylenediamine was accompanined by a partial hydrolytic cleavage of the lactone ring and gave an unique 6,6-type polyamide containing both lactone rings and hydrophilic groups such as carboxyl- and hydroxyl-groups. To determine the optimal conditions for interfacial polycondensation, the influence of the following factors on yield, value of intrinsic viscosity, and ring-opening ratio of polyamide was studied: volume of phase solvent, molar ratio of diamine to acid dichloride, molar ratio of sodium hydroxide as a hydrogen chloride acceptor to acid dichloride, temperature of reaction, the kinds of hydrogen chloride acceptors and organic phases, and contribution of stirring. The resulting polyamide was highly soluble in methanol, which is a poor solvent for conventional polyamides. A transparent and flexible film prepared from the methanol solution by a casting technique had a glass transition temperature of 88°C and a water absorption of ca. 30% at 95% relative humidity. Furthermore, the carboxylato-containing polyamide modified by treatment with potassium hydroxide was very soluble in water.