Evaluation of Schiff bases of 2,5-dimercapto-1,3,4-thiadiazole as photostabilizer for poly(methyl methacrylate) |
| |
Authors: | Emad Yousif Emaad Bakir Jumat Salimon Nadia Salih |
| |
Institution: | 1. Department of Chemistry, College of Science, AL-Nahrain University, Baghdad, Iraq;2. School of Chemical Science and Food Technology, Faculty of Science and Technology, University Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia |
| |
Abstract: | The photostabilization of poly(methyl methacrylate) (PMMA) films by Schiff bases of 2,5-dimercapto-1,3,4-thiadiazole compounds was investigated. The PMMA films containing concentration of complexes 0.5% by weight were produced by the casting method from chloroform solvent. The photostabilization activities of these compounds were determined by monitoring the hydroxyl index with irradiation time. The changes in viscosity average molecular weight of PMMA with irradiation time were also tracked (using benzene as a solvent). The quantum yield of the chain scission (Φcs) of these complexes in PMMA films was evaluated and found to range between 4.19 × 10?5 and 8.75 × 10?5. Results obtained showed that the rate of photostabilization of PMMA in the presence of the additive followed the trend:1] > 2] > 3] > 4] > 5].According to the experimental results obtained, several mechanisms were suggested depending on the structure of the additive. Among them, UV absorption, peroxide decomposer, and radical scavenger for photostabilizer mechanisms were suggested. |
| |
Keywords: | Photochemistry PMMA UV–Vis spectroscopy Photostabilizer UV absorber 2 5-Dimercapto-1 3 4-thiadiazole Schiff base |
本文献已被 ScienceDirect 等数据库收录! |
|