The Effect of New Metal Complexes on the Photo Degradation of Poly(vinyl chloride) Films.

Abstract

In the present work, the photo degradation of poly (vinyl chloride) films (80μ m
in thickness) has been studied using two complexes, these are:
1. Sodium –bis (3-mercapto-5-salicyldimino-1,2,4,-thiodiazole) dichlorochromate
(III)
2. bis (3-mercapto-5-salicyldimino-1,2,4,-thiodiazole) diaqua iron(III)
chloride .
The prepared complexes were identified by spectral methods (infrared&
ultraviolet- visible spectroscopy) as well as by C.H.N .and (M) analyses and
conductivity technique . The degree of photo degradation was monitored by
measuring the carbonyl index using I.R spectrophotometry .
The variation of the number average molecular weight of P.V.C films during
irradiation (λ =254nm) was determined by viscometric technique, as well as the
determination of quantum yield of scission (Фcs) through following the changes in
electronic spectra of samples.
According to the kinetic data and other experimental results , it is found that the Cr
(III) complex stabilizes the P.V.C films , while Fe(III) complex enhances the photo
degradation and this was confirmed by the suggested mechanism under the
experimental conditions employed .