کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5202157 | 1381890 | 2013 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Solid state polymerization of poly(lactic acid): Some fundamental parameters
ترجمه فارسی عنوان
پلیمریزاسیون جامد پلی (اسید لاکتیک): برخی از پارامترهای اساسی
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کلمات کلیدی
پلیمریزاسیون جامد پلی استرهای آلیفاتیک، پلی (اسید لاکتیک)، هیدرولیز حالت جامد، بلورسازی،
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
چکیده انگلیسی
Poly(lactic acid) (PLA) was submitted to solid state polymerization (SSP) in a fixed bed reactor under nitrogen flow, so as to examine technique efficiency for increasing the molecular weight and hence permitting the reduction of the melt polymerization residence times. In order to use a suitable starting material, SSP prepolymers of low and medium molecular weight were first prepared through solid state hydrolysis of commercial PLA grade under acidic and alkaline conditions. During these degradation runs, hydrolysis involved the random scission of ester groups in the polymer backbone, while the relevant kinetics and the resulting thermal properties were also examined. In a subsequent step, the prepolymers obtained were subjected to SSP at three temperatures, approximately 2.5-25.0 °C below their melting point. The process achieved an increase of up to 1.7 times the initial molecular weight, however, with different trends depending on the prepolymer characteristics, reaction temperature and time, as well as the pH of the hydrolysis medium. In addition to molecular weight build up, the effect of the SSP process on end product thermal properties was also investigated.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer Degradation and Stability - Volume 98, Issue 12, December 2013, Pages 2473-2481
Journal: Polymer Degradation and Stability - Volume 98, Issue 12, December 2013, Pages 2473-2481
نویسندگان
Stamatina Vouyiouka, Pavlos Theodoulou, Antonia Symeonidou, Constantine D. Papaspyrides, Rudolf Pfaendner,