Thermal decomposition of unsaturated materials

Unsaturated polymers thermally degrade by a number of different mechanisms depending on the structure of the polymer and the experimental conditions. By use of deuterium tagging it was shown that polyisobutylene degrades stepwise from the end by a cyclic unimolecular mechanism. Volatile products from isotactic polypropylene contained 75% propane at 340°, 64% n‐pentane at 375° and 49% propylene plus 12% isobutylene at 495°. Polyethylene was shown to give mostly propylene at lower temperatures but gave a 60% yield of ethylene at 600°.