Soluble copolymers via oxidative polymerization of pyrimidylamine and anisidine

A series of copolymers was synthesized by oxidative polymerization of 2-pyrimidylamine (MA) and o-anisidine (AS) with five monomer ratios using ammonium persulfate as an oxidant in 1 M HCl aqueous solution at room temperature. The yield, intrinsic viscosity, and solubility of the MA/AS copolymers were studied in detail. The copolymers were characterized by 1H NMR, FT-IR, wide-angle X-ray diffraction, and thermogravimetry. Based on 1H NMR spectra of the copolymers, the actual MA/AS molar ratio in the copolymers was compared with their feed ratio. The results showed that the MA/AS copolymers are amorphous and their polymerization yield, intrinsic viscosity, solubility in common organic solvent, thermostability, as well as activation energy of thermal degradation all increase with increasing AS content, but their char yield at 700°C in nitrogen decreases.