Preparation and characterization of soluble terpolymers from m-phenylenediamine, o-anisidine, and 2,3-xylidine

A series of terpolymers were synthesized by the chemical oxidative polymeri zation of m-phenylenediamine (MPD), o-anisidine (AS), and 2,3-xylidine (XY) in hydrochloride aqueous medium. The yield, intrinsic viscosity, and solub ility of the terpolymers were studied by changing the MPD/AS/XY molar ratio from 100/0/0 to 53/39/8 to 0/100/0. It was discovered that the MPD/AS= ter polymers exhibit a higher polymerization yield and better solubility than M PD/AS and MPD/XY bipolymers having the same MPD molar content. The as-prepa red MPD/AS/XY terpolymer bases were characterized by Fourier transform infr ared, ultraviolet-visible, H-1 NMR, and high-resolution solid-state C-13 NM R spectroscopies; wide-angle X-ray diffraction; and thermogravimetry. The r esults suggested that the oxidative polymerization from MPD, AS, and XY is exothermic, and the resulting terpolymers are more easily soluble in some o rganic solvents than MPD homopolymer. The copolymer obtained was a real ter polymer containing MPD, AS, and XY units, and the actual MPD/AS/XY molar ra tio calculated by solid-state C-13 NMR spectra of the polymers is very clos e to the feed ratio, although the AS content calculated on the basis of the H-1 NMR spectrum of the soluble part of the polymer is higher than the fee d AS content. The terpolymers and MPD homopolymer exhibit a higher polymeri zation yield and much higher intrinsic viscosity and are more amorphous tha n the AS homopolymer. At a fixed MPD content of 70 mol %, the terpolymers e xhibit an increased thermostability and activation energy of the major degr adation in nitrogen and air with an increasing AS content. (C) 2001 John Wi ley & Sons, Inc.