Abstract
We may now consider thermal and light initiated oxidative degradation in halogen-containing carbon-based polymers to occur through a radical-chain mechanism. Obviously the process is initiated by radical products of degradation in macromolecules, particularly by alkoxyl and hydroxyl radicals originating in the breakdown in the polymer of hydroperoxides. The development of the chain process occurs with the splitting out of atoms of hydrogen and halogen, resulting in dehydrochlorination to form double bonds and breaking down of the macromolecule. Although until recently there has been no very well-defined indication of the mechanism of formation, development, and splitting of the chains through thermal and light-oxidative degradation of Polyvinylchloride (PVC) it may be asserted that the most effective inhibition of this process is possible only by using materials which have the ability to accept radicals. Naturally, the radical acceptors employed can only be those which on heating, and exposure to the presence of air will not form hydroperoxides capable of reinitiating the destructive processes. Of major theoretical and practical interest in this connection, there have been described investigations on the effect of thermoxidative degradation in PVC, by a certain type of recently synthesized polyphenylvinylene (PPV) also containing the conjugated bonds of the degradation products of some high polymers, in particular PVC.
Effect of MEA's Degradation Products on Corrosion at CO2 Capture Plants
