Improved photostability of PVC films in the presence of 2-thioacetic acid-5-phenyl-1,3,4-oxadiazole complexes

Authors : Emad A YOUSIF, Salah M ALIWI, Ameer A AMEER

Pages : 399-410

View : 21 | Download : 10

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :The photostabilization of polyinsert ignore into journalissuearticles values(vinyl chloride); insert ignore into journalissuearticles values(PVC); films by 2-thioacetic acid-5-phenyl-1,3,4-oxadiazole with Sninsert ignore into journalissuearticles values(II);, Bainsert ignore into journalissuearticles values(II);, Niinsert ignore into journalissuearticles values(II);, Zninsert ignore into journalissuearticles values(II);, Cuinsert ignore into journalissuearticles values(II);, and Cainsert ignore into journalissuearticles values(II); complexes was investigated. PVC films containing different concentrations of complexes ranging from 0.1% to 0.5% by weight were produced by the same casting method from THF solvent. The photostabilization activities of these compounds were determined by monitoring the carbonyl and polyene indices with irradiation time. The changes in viscosity average molecular weight of PVC with irradiation time were also tracked insert ignore into journalissuearticles values(using THF as a solvent);. The quantum yield of the chain scission insert ignore into journalissuearticles values(F cs); of these complexes in PVC films was evaluated and found to range between 4.94 \times 10-8 and 1.61 \times 10-7. The results obtained showed that the rate of photostabilization of PVC in the presence of the additive follows the trend: Sninsert ignore into journalissuearticles values(OX);2 > Bainsert ignore into journalissuearticles values(OX);2 > Zninsert ignore into journalissuearticles values(OX);2 > Niinsert ignore into journalissuearticles values(OX);2 > Cuinsert ignore into journalissuearticles values(OX);2 > Cainsert ignore into journalissuearticles values(OX);2 > OX Based on the experimental results obtained, several mechanisms were suggested depending on the structure of the additive. HCl scavenging, UV absorption, peroxide decomposer and radical scavenger for photo-stabilizer additives mechanisms were suggested.
Keywords : Photostabilizer, PVC, oxadiazole