Chapter 4 Oxidative Degradation of Polymers
1975; Linguagem: Inglês
10.1016/s0069-8040(08)70336-4
Autores Tópico(s)Polymer crystallization and properties
ResumoIn an atmosphere containing oxygen, polymers are oxidized, partially degraded, and crosslinked. The exposure of a polymer to oxygen is characterized by an induction period during which the polymer does not show any obvious changes and there is no evidence of oxygen absorption. This period is nevertheless important in the process of polymer oxidation because small amounts of hydroperoxides are formed and they initiate the subsequent rapid auto-oxidation of the polymer. An increase in temperature reduces the induction period and accelerates the auto-oxidation. In some cases, when the polymer contains trace amounts of peroxide impurities or catalysts such as metallic salts, the induction period is not observed at all and the process of catalytic oxidation begins immediately. The decomposition of the hydroperoxides is commonly recognized as the process responsible for further rapid oxidation. The chapter particularly focuses on the chemical and physical factors that are responsible for the formation of hydroperoxides during the induction period that influence the mechanism of polymer oxidation.
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