کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5190566 1381211 2005 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Sequence distribution, crystallization and melting behavior of poly(ethylene terephthalate-co-trimethylene terephthalate) copolyesters
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Sequence distribution, crystallization and melting behavior of poly(ethylene terephthalate-co-trimethylene terephthalate) copolyesters
چکیده انگلیسی
The compositions of a series of copolyesters of ethylene- and trimethylene- terephthalate were determined by NMR. The values of randomness parameter revealed these copolyesters were random copolymers with average-number sequence lengths varied from 1 to 10. These copolyesters were investigated using temperature-modulated differential scanning calorimeter (TMDSC) and wide angle X-ray diffractometer (WAXD). The crystallization behavior was evidenced from the non-isothermal DSC thermograms and WAXD patterns. The crystallization rate and the intensity of diffraction peaks decrease with increasing the minor co-monomer content. The copolyester with equal amounts of monomers is still crystallizable even though the average sequence length is only 2.0, and its WAXD pattern is quite different from those of homopolymers. In the melting study, three distinct peaks of reversing melting were observed. Two peaks in the high temperature side are due to remelting of the recrystallized crystals formed during the heating scan, whereas the highest temperature peak is attributed to the melting of the crystals that are formed in relatively high temperature. The results of WAXD and TMDSC support the mechanism of melting-recrystallization-remelting for the multiple melting behaviors.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 46, Issue 20, 23 September 2005, Pages 8752-8762
نویسندگان
, , , ,