کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5189671 | 1381189 | 2005 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Enzyme-catalyzed polymerization and degradation of copolyesters of ε-caprolactone and γ-butyrolactone
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Copolymers of γ-butyrolactone (γ-BL) and ε-caprolactone (ε-CL) were successfully synthesized by ring-opening polymerization using Novozyme-435 (immobilized lipase B from Candida antartica) as catalyst. Copolymers with different compositions were obtained and characterized by 1H NMR, 13C NMR, GPC, DSC and X-ray diffraction. Increasing the [BL]/[CL] feed ratio resulted in decreases of molecular weight (Mn) of copolymers and reaction yield. Moreover, the BL contents in the copolymers varied according to the feed ratio. The Tm of the copolymers decreased from 58 to 49 °C with increase in BL content from 0 to 14%. The resulting copolymers were all semicrystalline with a PCL-type crystalline structure. Solution cast films were allowed to degrade in a pH 7.0 phosphate buffer solution containing Pseudomonas lipase. Weight loss data showed that the degradation rate of copolymers in the presence of Pseudomonas lipase decreased with the increase of BL contents.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 46, Issue 26, 12 December 2005, Pages 12682-12688
Journal: Polymer - Volume 46, Issue 26, 12 December 2005, Pages 12682-12688
نویسندگان
Feng He, Suming Li, Henri Garreau, Michel Vert, Renxi Zhuo,