کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5420803 | 1507516 | 2006 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
How we can interpret the T1 dispersion of MC, HPMC and HPC polymers above glass temperature?
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: How we can interpret the T1 dispersion of MC, HPMC and HPC polymers above glass temperature? How we can interpret the T1 dispersion of MC, HPMC and HPC polymers above glass temperature?](/preview/png/5420803.png)
چکیده انگلیسی
The chain dynamics in methyl cellulose (MC), hydroxypropylmethyl cellulose (HPMC) and hydroxypropyl cellulose (HPC) were studied with the aid of field-cycling NMR relaxometry technique in the temperature range from 300 to 480 K that is above the glass transition, but below thermal degradation. The frequency dependence of proton spin-lattice relaxation time was determined between 24 kHz and 40 MHz for selected temperatures. The experimental spin-lattice relaxation dispersion data were fitted with the power law relations of T1âÏγ predicted by the tube/reptation model. The exponent's values found from the fitting procedure for MC, HPMC and HPC almost exactly match the ones predicted in tube/reptation model for limit II (γ=0.75) and in MC also for limit III (γ=0.50). Remarkably, this finding concerns the polymers in networks formed of the same polymer species.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Solid State Nuclear Magnetic Resonance - Volume 30, Issues 3â4, October 2006, Pages 192-197
Journal: Solid State Nuclear Magnetic Resonance - Volume 30, Issues 3â4, October 2006, Pages 192-197
نویسندگان
Adam Rachocki, Joanna Kowalczuk, Jadwiga Tritt-Goc,