| Popis: |
A comparative study has been made of the thermal degradations of oligo-isobutylenes having carboxyl or ketonic end groups with that of polyisobutylene as model. The oligo-isobutylenes have found less heat-resistant owing to their content of unstable low mol. wt. fractions, the lower CC bond strength adjacent to the end groups, and to an exothermic chain-transfer reaction at the carboxyl group, in which hydrogen abstraction is coupled with fragmentation and CO 2 liberation, which is followed by a macromolecular decomposition from the chain ends. |
