کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5204960 1381976 2006 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Solvent effect on thermal degradation of plasticized para-substituted polystyrenes
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Solvent effect on thermal degradation of plasticized para-substituted polystyrenes
چکیده انگلیسی

The thermal effect on stability of a series of para-substituted polystyrenes with methyl, methoxy and α-methyl substituents in various solvents was studied in the temperature range of 298-363 K. They gave a monomer fluorescence as a minor part and excimer fluorescence as a major part. Thermal heating of para-substituted polystyrenes shows a decrease in both monomer and excimer fluorescences in all used solvents. Thermal heating causes a small fluorescence quenching effect at lower temperatures in solution but becomes very dominant at higher temperatures. Added terephthalate and phthalate plasticizers to these para-substituted polystyrenes caused a quenching of both monomer and excimer fluorescences without the formation of exciplex emission. The thermal quenching processes of the plasticized polymers were accompanied by a change in the structure of the fluorescence spectra at high heating temperatures. This may indicate that thermodestruction of these polymers starts from a random chain scission. The change in solvent polarity has considerable effect on fluorescence quenching but it has a minor effect on the thermal degradation of these polymers. The binding energies for excimer formation were calculated in the used solvents.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer Degradation and Stability - Volume 91, Issue 12, December 2006, Pages 3252-3258
نویسندگان
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