کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
12540 799 2005 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The effect of crystallinity on the deformation mechanism and bulk mechanical properties of PLLA
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی بیو مهندسی (مهندسی زیستی)
پیش نمایش صفحه اول مقاله
The effect of crystallinity on the deformation mechanism and bulk mechanical properties of PLLA
چکیده انگلیسی

Poly (l-lactide) is a widely studied biomaterial, currently approved for use in a range of medical devices, however, most in vitro studies have so far focussed upon either the bulk properties during degradation and/or deformation, or on the microstructure of the unloaded material during degradation. This study aimed to combine these approaches through the technique of simultaneous small-angle X-ray scattering and tensile testing at various stages of degradation up to 8 months, on material with a range of induced microstructures. Results showed that the amorphous material deformed by crazing in the dry, wet and degraded states, however, the mechanism by which the craze developed changed significantly on hydration. Despite this difference, there was little change in the bulk mechanical properties. Crystalline materials deformed through crystal-mediated deformation, with contributions from both cavitation and fibrillated shear, but surprisingly, differences in the length scales within the spherulitic structure caused by annealing at different temperatures had very little effect on the mechanism of deformation, though differences were seen in the bulk properties. Furthermore, hydration had little effect on the crystalline materials, though degradation over 8 months resulted in loss of mechanical properties for samples produced at higher annealing temperatures. In conclusion, the introduction of crystallinity had a huge effect on both bulk and microscopic properties of PLLA, but the spherulitic structure of the crystalline material affected the bulk properties significantly more than it did the micromechanism of deformation.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biomaterials - Volume 26, Issue 29, October 2005, Pages 5771–5782
نویسندگان
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