Synthesis and Characterization of Poly(aniline-co-xylidine)s

Copolymers were synthesized by oxidative polymerization of aniline and 2,3-xylidine (XY) at five monomer ratios using ammonium persulfate as an oxidant in HCl medium. The yield and intrinsic viscosity of the copolymers were significantly dependent on monomer ratio. The copolymers were characterized by Fourier transform Infrared spectroscopy, 1Hnuclear magnetic resonance spectroscopy, wide-angle X-ray diffraction, DSC, and thermogravimetry. The results showed that the actual content of XY unit in the copolymers is much higher than feed XY unit content but 2,3-xylidine cannot homopolymerize under the same condition. The copolymers are amorphous and exhibit thermal decomposition temperature higher than 395°C, char yield larger than 22 wt% at 900°C in nitrogen. The activation energy of thermal decomposition for the copolymers decreased monotonically from 124kJ mol-1 to 42kJ mol-1 with increasing XY unit content from 10 to 90%.