Thermal degradation of polyvinyl-trimethyl-silane by pyrolysis gas chromatography

Pyrolysis Gas Chromatographic investigations have been carried out on a vinyl polymer containing silicon in the side-group. Comparison of the mechanism of degradation of isotactic polyvinyl-trimethyl-silane with those of other vinyl polymers indicates the importance of the side-group in the thermal decomposition of polymers of this type.We have identified the volatile pyrolysis products and studied the effect of pyrolysis conditions on their production. From the point of view of thermal degradation, polyvinyl-trimethyl-silane behaves like polypropylene but unlike polystyrene. During the degradation, random initiation is followed by intramolecular hydrogen abstraction, mainly leading to trimer. This reaction is faster than monomer formation by depropagation. We conclude that, in thermal degradation, the most important property of the side-group is not its size but its chemical nature.