Oxidative polymerization of o-phenylenediamine and pyrimidylamine

Oxidative polymerization of o-phenylenediamine and 2-pyrimidylamine (MA) wa s performed by using three molar ratios of ammonium persulfate as an oxidan t in boiling glacial acetic acid. The polymerization yield decreases signif icantly but the intrinsic viscosity of the polymers increases slightly with increasing the feed content of 2-pyrimidylamine. The resulting polymers we re characterized by H-1-nuclear magnetic resonance and Fourier transform In frared spectroscopies, wide-angle X-ray diffraction, and thermogravimetry. The results suggested that the polymers are amorphous and exhibit thermal d ecomposition temperatures higher than 560 degreesC; the maximum weight-loss rate was lower than 3.5%/min, char yield larger than 17 wt.% at 700 degree sC in nitrogen and air. The activation energy of thermal decomposition for the copolymers was 43-53 kJ/mol in nitrogen and air. (C) 2000 Elsevier Scie nce Ltd. All rights reserved.