Photooxidation of poly(vinyl chloride). 1. A reexamination of the mechanism

High doses gamma radiolysis of PVC: Mechanisms of degradation

“…In order to attribute these bands to the corresponding radiolysis products, we studied the radiolysis mechanisms of PVC proposed in literature [5,6,8,18,19], and the assignment of infrared bands of products formed by different degradations (UV, thermal, etc.) of PVC [20][21][22][23][24][25]. The band located at 1715 cm À1 could be attributed to the formation of ketones, aldehydes, acid chloride and/or carboxylic acids.…”

Principles of Uv Degradation

“…Gardette et al [17][18][19][20][21][22][23][24] used FTIR of original and derivatized products of photodegradation for identification of photoproducts. The following elements of the photooxidation mechanism were outlined: 17 • hydrogen abstraction leads to one of two possible radicals:…”

“…17 The above initial results were further investigated [18][19][20][21][22][23][24] to confirm the proposed mechanism and understand some of its features. These groups could not be properly identified.…”

Mechanism of Action of Titanium Dioxide Pigment in the Photodegredation of Poly(Vinyl Chloride) and Other Polymers

“…The polymer is subsequently photo-oxidised and the discoloration is then caused by residual polyenes. In more detail [19,20], when the PVC matrix is exposed to UV light of wavelengths longer than 300 nm, these competing reactions are activated, as follows:…”

“…␣, ␣′-chlorinated ketones 1745 cm -1 ; acid chlorides 1785 cm -1 ; ␤-chlorinated acids 1718 cm -1 . Schemes 3 and 4 show the summary and mechanism, [18,19,22] respectively, for the photodegradation of PVC.…”