Initiated oxidation of polyenes formed in the thermal degradation of PVC

Abstract

Polyenes formed in the thermal degradation of PVC are readily oxidized in the liquid phase in the presence of a radical initiator. In pure oxygen at a constant rate of initiation, different length polyenes are consumed by a first‐order reaction: the rate of consumption is proportional to the polyene length and to the square root of initiator concentration. Applying the relationships given by the theory of chain reactions, we determined the ratio of the rate constant of chain propagation calculated for one double bond k2 to the square root of the chain‐termination rate constant k4. The value obtained, which is relatively high in comparison to other unsaturated hydrocarbons, reflects very well the high reactivity of polyenes of the degraded PVC sample towards oxidation. Intramolecular chain propagation steps are also likely to play a role in the oxidation of polyenes.

Photostabilizing efficiency of ultraviolet light stabilizers for rigid poly(vinyl chloride) against photo‐oxidation

“…3a; Ref. 30). Also, this destruction can also process in the presence of alkylperoxide radicals (Fig.…”

Investigation of the Impact of Cold Plasma Treatment on the Chemical Composition and Wettability of Medical Grade Polyvinylchloride

“…The EDS study of the chemical composition of the pristine and plasma-treated PVC catheters indicated the growth of the concentration of oxygen in the near surface layers of plasma-treated PVC catheters, as demonstrated in Figure 8. The presence of oxygen in the pristine PVC is reasonably explained by its oxidation under high-temperature extrusion processing [47].…”

From recycled PVC and its blends to eco-friendly materials for the footwear industry in Brazil: Insight into the process and evaluation of the mechanical properties

“…2a) related to the polyenes suffering scission in the air. Nagy et al [19] discussed the oxidation mechanisms of polyenes during the thermal degradation of PVC, reporting that they occur in distinct steps. The last degradation stage was noted in the range from 480 to 530°C with an 18.0% mass loss, which can be related to the backbone of the polymer blend.…”