Catalytic action of metallic salts in autoxidation and polymerization. VI. The inhibitive effects of transition‐metal N,N‐diethyldiselenocarbamates on the thermal oxidative degradation of isotactic polypropylene

Abstract

synopsis Transition-metal (Zn, Ni, Pd, Cu, Cr, Co) N,N-diethyldiselenocarbamates were prepard, and the inhibitive effects of these compounds on the thermal oxidative degradation of isotactic polypropylene, both in the presence and absence of copper stearate as oxidation accelerator, were examined by conventional oxygen uptake. I n both cases, all metal selenocarbamates showed a pronounced inhibitive effect on the degradation of the polymer, especially Zn and Ni selenocarbamates. The inhibitive action of these metal selenocarbamates was discussed from the viewpoint of viscosity change and carbonyl and hydroperoxide contents.

Polymer Reaction. 9. Effect of Polymer-Bound Chromium on Oxidative Pyrolysis of Poly(propylene)

“…This action is undoubtedly the catalytic decomposition of poly(propylene) hydroperoxide by the chromium ion, such as POOH + Cr(III) -PO• + OH" + Cr(IV) (23) POOH + Cr(IV) -POO• + H+ + Cr(III) (24) On the other hand, if the chromium is in the form of thiocarbamate, then it possesses slight inhibitive effects on the autoxidation of poly (propylene). 31 The mechanism of this reaction has been elucidated32 for the more effective thiocarbamates of nickel and zinc. Based on the plausible structure for the chromylated poly(propylene), the metal ion would be expected to accelerate rather than inhibit the autoxidation of poly(propylene).…”