The mechanism of polyethylene oxidation

Abstract

Abstract As evidenced by formation of peroxides and carbonyl, reaction occurs during the oxidation induction period of polyethylene. The meaning of the term oxidation induction period is revealed by the tremendous change in melt index, carbonyl, density, color, tensile, and elongation occurring towards the end of this time period. Hydroperoxide forms long before the end of the oxidation induction period even in the presence of an antioxidant. At any temperature both chain scission and crosslinking occur simultaneously. The rate of oxidation is accelerated by increasing temperature, unsaturation, and branching. Molecular weight seems to have no effect.