کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1394731 1501363 2015 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Kinetics of the deformation induced memory effect in polyamide-6
ترجمه فارسی عنوان
سینتیک اثر حافظه ناشی از تغییر شکل در پلی آمید -6
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
چکیده انگلیسی


• Disk-shaped samples were realized with properties similar to the virgin pellets.
• The memory effect is purely governed by strain and saturates at a certain strain.
• An unusual and reversible phase-transition is observed for the sample without shear.

Nascent polyamide-6 shows a peculiar and irreversible effect; the quiescent crystallization kinetics on cooling are accelerated upon deformation in the melt, even after full relaxation of the melt. This phenomenon, known as the orientation (or better, deformation) induced memory effect of polyamide materials, is explored in a step-by-step manner using in-situ wide-angle X-ray diffraction. For this purpose, unique polyamide-6 samples were used, which were created by compression moulding the virgin pellets just below the average melting temperature, defined by the peak position in a DSC-curve. The experimental data shows that only the imposed strain level controls the irreversible change in the quiescent crystallization kinetics. During cooling of the undeformed melt, an unusual crystallization behaviour is observed, i.e. the stable αα-phase converges into the less stable ββ-mesophase. Possible causes for the memory-effect are discussed and related to hypotheses from the literature.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: European Polymer Journal - Volume 72, November 2015, Pages 296–308
نویسندگان
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