کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5203525 | 1381933 | 2009 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Lipase-catalysed degradation of copolymers prepared from É-caprolactone and dl-lactide
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Lipase-catalysed degradation of copolymers prepared from É-caprolactone and dl-lactide Lipase-catalysed degradation of copolymers prepared from É-caprolactone and dl-lactide](/preview/png/5203525.png)
چکیده انگلیسی
A series of copolymers were prepared by ring-opening polymerization of É-caprolactone and dl-lactide, using zinc lactate as catalyst. The resulting PCL/PLA copolymers were characterized by various analytical techniques such as NMR, SEC, DSC and X-ray diffraction. The [CL]/[LA] ratios of the copolymers are very close to those in the feed, indicating a good conversion of monomers. The copolymers with CL contents higher than 50% appear semi-crystalline, the crystalline structure being of the PCL-type. Compression moulded polymer films were allowed to degrade in a pHÂ =Â 7.6 phosphate buffer containing Pseudomonas lipase. Data show that copolymers with CL contents lower than 25% are not degradable and the degradation rate increases with CL content for CL-rich copolymers. Various soluble degradation products are detected in the degradation medium, including CL1 to CL3 and LA1 to LA4 homo-oligomers, and CL2LA1 co-oligomer. The presence of LA homo-oligomers and CL2LA1 co-oligomer suggests that Pseudomonas lipase can not only degrade PCL but also LA short blocks along PCL/PLA copolymer chains. On the other hand, little changes of composition are detected during degradation, in agreement with a surface erosion mechanism as shown by ESEM.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer Degradation and Stability - Volume 94, Issue 4, April 2009, Pages 688-692
Journal: Polymer Degradation and Stability - Volume 94, Issue 4, April 2009, Pages 688-692
نویسندگان
Sebastien Lenglet, Suming Li, Michel Vert,