کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10609880 984736 2011 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Influence of crystal polymorphism on mechanical and barrier properties of poly(l-lactic acid)
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Influence of crystal polymorphism on mechanical and barrier properties of poly(l-lactic acid)
چکیده انگلیسی
The effect of crystal polymorphism on barrier and mechanical properties of PLLA is detailed in this contribution. PLLA films containing different amounts of α and α′ crystal forms were prepared by annealing quenched PLLA at different temperatures. The polymorphic structure of the films was analyzed by X-ray diffraction. Mechanical properties and permeability to water vapor were investigated as a function of degree of crystallinity (wC) and related to crystal polymorphism developed during annealing. The polymorphic structure of PLLA significantly affects mechanical and barrier properties. The α crystal modification provides a better barrier to water vapor and a higher Young's modulus, compared to films containing the α′ modification, but a lower elongation at break. The varied barrier and mechanical properties were correlated to the different packing of PLLA chains in the two analyzed polymorphs. The conformational disorder of the α′ form makes this structure a mesophase (condis crystal), with remarkable effects on material properties.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: European Polymer Journal - Volume 47, Issue 5, May 2011, Pages 1073-1080
نویسندگان
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