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Iranian Journal of Chemistry and Chemical Engineering، جلد ۱۵، شماره ۲، صفحات ۸۷-۹۲
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| عنوان فارسی |
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| چکیده فارسی مقاله |
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| عنوان انگلیسی |
Probing the Cure and Postcure Reactions in Polyurethanes by FTIR and GPC |
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| چکیده انگلیسی مقاله |
Fourier transform infrared (FTIR) and gel permeation chromatography (GPC) wre respectively utilized in determining the changes in isocyanate (NCO) concentration and molecular weight (MW) and its distribution (MWD) in polyurethanes during their cure and postcure stages. Samples, originally cured at 45°C, were taken through accelerate aging tests at various temperatures. The FTIR and GPC analytical conditions were optimized, for both molecular weight and molecular weight distribution and NCO group determination. In FTIR spectroscopy Beer's law was obeyed over the ranges: 2.33-22.34 and 0.03-1.61 mmol lit-1. RSD, detection limit and molar absortivity were found to be 1.46%, 4´10-6 mol lit-1 and 1095 lit mol-1 cm-1 respectively. It was found the NCO concentration decreases with the progress of polymerization and at the same time MW of the sol increases, going through a maximum and then decreases to a constant level. The time to reach this level and termination of NCO concentration, i.e., the end of polymerization decreases with the increase in temperature. The results obtained from GPC and FTIR methods in following the different steps of polymerization as well as those from the linear plots of the end time of reaction vs. the 1/T, were in good agreement. |
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| نویسندگان مقاله |
حامد صالحی |
department of chemistry, faculty of science, tarbiat modarres university, p.o. box 14155-4838 tehran, i.r. iran
سازمان اصلی تایید شده: دانشگاه تربیت مدرس (Tarbiat modares university)
مظفر اسلامی |
research institute of petroleum industry ripi , p.o. box 18745-4391 tehran, i.r. iran
سازمان اصلی تایید شده: پژوهشگاه صنعت نفت (Research institute of petroleum industry)
محمدنبی سربلوکی | mohammad nabi
institute of biochemistry and biophysics, tehran university, p.o. box 13145-1384 tehran, i.r. iran
سازمان اصلی تایید شده: مرکز تحقیقات بیوشیمی و بیوفیزیک (Institute of biochemistry and biophysics)
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| نشانی اینترنتی |
http://www.ijcce.ac.ir/article_10437_f89ec3d14b8db86570a96ca3a92403fd.pdf |
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| زبان مقاله منتشر شده |
en |
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