Synthesis and Photostability Study of Some Modified Poly(vinyl chloride) Containing Pendant Benzothiazole and Benzimidozole Ring

Abstract

The influence of introducing benzothiazole and benzimidazole as a pending groups into the repeating unit of PVC hasbeen studied on the bases of photostability measurements. The photostability of modified polymers were studied bymonitoring the carbonyl Index (ICO), polyene index (Ipo) and hydroxyl index (IOH), all results obtained indicated thatPAA, PSS, PNN, PSA and PNA gave lower growth rate of ICO, IPO and IOH with irradiation time with respect tounmodified PVC film (control). The following trends of photostability are obtainedPAA>PSS>PNN>PSA>PNAAccording to the experimental results several reaction mechanisms were proposed depending on the presence ofbenzothiazole and benzimidazole moieties in the polymer chain. The mode of chain scission was also investigated bymeasuring the variation of average viscosity molecular weight with irradiation time for modified PVC. The degree ofdeterioration (?) and the average number of chain scission (S) values were also calculated.