Synergy Effects of Binary and Ternary Mixtures of Inhibitors in the Process of Polypropylene Autooxidation

Abstract

The autooxidation of the solid isotactic polypropylene, inhibited with three different additives-phenol, amine and nitroxy radical as well as their binary and tertiary mixtures was investigated. Noticeable synergy effects were observed for inhibiting systems: phenol-amine and phenol - nitroxy radical; these effects were especially high in the region of low concentrations of inhibitors, in the so called subcritical region.

Mathematical model was proposed for the evaluation of contribution of each inhibitor to the induction period. Possibility of such description was confirmed by comparison of the experimental and calculated data.

Key Words:

• Isotactic polypropylene
• autooxidation
• inhibitors
• phenol
• amines
• mixtures of inhibitors