کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5191919 | 1381243 | 2005 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Biodegradable multiblock PEO/PLA thermoplastic elastomers: molecular design and properties
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Given the need for highly flexible biodegradable polymers, a series of poly(ethylene oxide)/poly(l-lactic acid) (PEO/PLA) (PELA) multiblock poly(ether-ester-urethane)s, were synthesized and characterized. The first step of the synthesis consisted of the ring-opening polymerization of l-lactide, initiated by the hydroxyl terminal groups of the PEO chain, followed by the chain extension of these PLA-PEO-PLA triblocks, using hexamethylene diisocyanate (HDI). The trimers comprised PEO segments in the 1000-10,000 molecular weight range, with the length of each PLA block covering the 200-10,000 interval. DSC and X-ray analyses revealed that, depending on their composition, amorphous matrices, monophasic crystalline materials and copolymers comprising two crystalline phases, were generated. The multiblock copolymers synthesized exhibited superior mechanical properties, with ultimate tensile strength values around 30Â MPa, Young's moduli as low as 14Â MPa and elongation at break values well above 1000%. Because of their phase segregated morphology, most of these multiblock copolymers displayed remarkable mechanical properties also when fully hydrated, with typical UTS values around 9Â MPa.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 46, Issue 7, 10 March 2005, Pages 2068-2075
Journal: Polymer - Volume 46, Issue 7, 10 March 2005, Pages 2068-2075
نویسندگان
D. Cohn, A. Hotovely-Salomon,