Thermal decomposition of poly(2-vinylpyridine): Effect of complexation with copper chloride

The thermal decomposition of complexes between poly(2-vinylpyridine) (P2VPy) and copper chloride was investigated by several techniques, including thermogravimetric analysis and mass spectrometry. P2VPy was selected as the host polymer for two reasons: its ability to form complexes with copper compounds which are soluble in high concentrations, and because it forms essentially no char upon pyrolysis. The decomposition mechanism of P2VPy changes significantly upon complexation with copper compounds. P2VPy was initially thought to be an ideal ligand for the pyrolytic formation of pure copper owing to its low carbon yield upon thermal decomposition. The presence of copper chloride during polymer decomposition alters the decomposition mechanism of the polymer and accounts for significant yields of carbonaceous char. The magnitude of this effect is dependent upon the quantity of copper present. Polymer char yields as high as 41 wt% have been obtained when each pyridine moiety is complexed by CuCl₂. Studies based on the model compound Cu(2-picoline)₂Cl₂ indicate that the diffusion length of released volatiles plays a significant role in the observed decomposition mechanisms.