کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5187278 1381125 2008 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Markedly compressible behaviors of gellan hydrogels in a constrained geometry at ultraslow strain rates
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Markedly compressible behaviors of gellan hydrogels in a constrained geometry at ultraslow strain rates
چکیده انگلیسی

The fracture behaviors of gellan hydrogels under compression remarkably depend on the strain rate as well as the boundary conditions for lateral expansion. In the geometry with no constraint for lateral expansion (conventional uniaxial compression), the gels rupture at relatively small strains independently of the compression rates. In contrast, when the gels are compressed extremely slowly (at a strain rate of ca. 10−5 s−1) in the geometry prohibiting the lateral expansion at their top and bottom surfaces, they are remarkably compressible down to 2% of the initial height without macroscopic fracture and they are accompanied by a large amount of water release. In such markedly compressed gels, many microscopic cracks are formed around the central layer, where strain concentration occurs due to the nonuniform deformation arising from the constrained geometry. In the highly compressible case, the formation of macroscopic cracks is prevented by the localization of microscopic cracks as well as the enhancement in mechanical toughness by a significant increase in polymer concentration due to water release.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 49, Issue 15, 7 July 2008, Pages 3295-3300
نویسندگان
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