Synthesis and Properties of Nylon Copolymers by Interfacial Polycondensation

Abstract

Nylon 66-6I and nylon 610-6I copolymers (I=isophthalic acid) were prepared by melt polycondensation (Random) and by interfacial polycondensation using carbon tetrachloride (CCl₄) or chloroform (CHCl₃) as organic solvent. Melting temperature (T_m), glass-transition temperature (T_g) and cold crystallization temperature (T_cc) of the copolymers were measured by a differential thermal analyzer. For nylon 66-6I, T_m decreased in the order of Random>CCl₄>CHCl₃, while T_g, T_cc and T_cc-T_g increased in the order of Random<CHCl₃<CCl₄. For nylon 610-61, on the other hand, T_m, T_g, and T_cc differed little between Random and CCl₄. It is suggested from the above results that nylon 66-6I copolymers prepared by interfacial polycondensation form a block structure which enhances the rigidity of copolymer chains when aromatic chain content and hydrogen bond concentration are relatively high.