The effect of mechanical loads on the low temperature oxidation of polymers and the effect of ozone-oxygenous action on isotactic polypropylene

Abstract

A study has been made of the effect of mechanical loads on the rate of low-temperature oxidation of isotactic polypropylene by an ozone-oxygen mixture. It is shown that loading increases the rate of chemical degradation of PP. An essential difference has been detected in the character of dependences of the rate of accumulation of carbonyl groups on stress and strain. Under a regime with σ=const the main factor is the presence of overstrained bonds whose reactivity is higher. A superposition of three factors takes place with ε=const: the presence of residual stress, increase in the kinetic flexibility of macrochains and an alteration in the orientation of chain segments.