Effect of concentration of atactic polypropylene on its rate of autoxidation

Abstract

SynopsisA general scheme previously reported for the autoxidation of polyolefins is further substantiated by results obtained for the uncatalyzed and catalyzed autoxidation of various concentrations of atactic polypropylene (APP) (by admixture with polyisobutylene) under various experimental conditions. Thus, rates of maximum carbonyl formation were measured as a function of APP concentration at 12OoC, oxygen concentrations ranging from 0.5%-100% by volume and cobaltic acetylacetonate catalyst concentrations (3 and 17) X lo-' molef7.5 mg sample. Good agreement was found between experimentally observed and theoretical dependencies of the maximum carbonyl formation rate on APP concentration derived from the combined reaction scheme.

The Natural Rubber/Zinc Oxide Nanocomposites: Its Morphology, Mechanical and Thermal Decomposing Properties

“…With the increment in nano-ZnO content, the initial decomposing temperature decreased, the maximal decomposing temperature, however, decreased then increased and finally approached that of pure NR. Previous studies [5][6][7] had shown that, the metal consists of variable valence would cause electron transferring and accelerate the production of free radicals to speed up the rupture of rubber hydrocarbons, resulting in the thermal degradation of rubber hydrocarbons and the production in ageing resistance. And the Zinc ion in the Nano-ZnO just possesses such a function.…”