STRUCTURE AND PROPERTIES OF WHOLLY AROMATIC NYLON COPOLYMERS

Wholly aromatic nylon copolymers were prepared by low-temperature solution polycondensation in N-methyl-2-pyrrolidone solvent from diamine of p-phenylene(P) or m-phenylene(M) and diacid chloride of terephthaloyl(T) or isophthaloyl(I). Copolymer compositions measured by IR method for P/M-I copolymers are nearly equal to comonomer compositions. Melting point measured by DTA method and crystallinity measured by X-ray method decrease and solubility increases, by the copolymerization. Films were prepared by casting from as-polymerized solutions of P/M-I copolymers. Tensile strength, Young's modulus, elongation and dynamic modulus near room temperature increase with increasing comonomer content. Retention of dynamic modulus at higher temperature increases with increasing P content of copolymers. Some discussion was made on these results.