کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5144500 1496865 2018 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Control of molecular weight distribution in synthesis of poly(2-hydroxyethyl methacrylate) using ultrasonic irradiation
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Control of molecular weight distribution in synthesis of poly(2-hydroxyethyl methacrylate) using ultrasonic irradiation
چکیده انگلیسی
Poly(2-hydroxyethyl methacrylate) (PHEMA) was synthesized using ultrasonic irradiation without any chemical initiator. The effect of the ultrasonic power intensity on the time course of the conversion to polymer, the number average molecular weight, and the polydispersity were investigated in order to synthesize a polymer with a low molecular weight distribution (i.e., low polydispersity). The conversion to polymer increased with time. A higher ultrasonic power intensity resulted in a faster reaction rate. The number average molecular weight increased during the early stage of the reaction and then gradually decreased with time. A higher ultrasonic intensity resulted in a faster degradation rate of the polymer. The polydispersity decreased with time. This was because the degradation rate of a polymer with a higher molecular weight was faster than that of a polymer with a lower molecular weight. A polydispersity below 1.3 was obtained under ultrasonic irradiation. By changing the ultrasonic power intensity during the reaction, the number average molecular weight can be controlled while maintaining low polydispersity. When the ultrasonic irradiation was halted, the reactions stopped and the number average molecular weight and polydispersity did not change. On the basis of the experimental results, a kinetic model for synthesis of PHEMA under ultrasonic irradiation was constructed considering both polymerization and polymer degradation. The kinetic model was in good agreement with the experimental results for the time courses of the conversion to polymer, the number average molecular weight, and the polydispersity for various ultrasonic power intensities.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ultrasonics Sonochemistry - Volume 40, Part A, January 2018, Pages 736-741
نویسندگان
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