Synthesis and characterization of a soluble terpolymer from pyridylamine, aniline and xylidine

dA series of soluble terpolymers was synthesized by oxidative polymerizatio n of 2-pyridylamine, aniline, and 2,3-xylidine using ammonium persulfate as oxidant in 1 M HCl aqueous solution. The yield, intrinsic viscosity, and s olubility of the terpolymers were studied by changing monomer ratio and the polymerization time. At a fixed xylidine content of 10 mol%, the yield and intrinsic viscosity of the terpolymers decrease with increasing pyridylami ne content and remain almost constant with polymerization time. The resulti ng terpolymers were characterized by FT-IR, H-1-NMR, wide-angle X-ray diffr action, and thermogravimetry. The results showed that the polymers are amor phous terpolymers and exhibit good solubility, decomposition temperature of 375-495 degreesC, the maximum weight-loss rate of 0.9-5.8%/min, high char yield of 65 wt.% at 700 degreesC in nitrogen, and thermal degradation activ ation energy of 25-81 kJ/mol. The thermal stability of the terpolymers is g enerally higher in nitrogen than in air. (C) 2001 Elsevier Science Ltd. All rights reserved.