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(CTEI网讯) 会议:第十二届亚洲纺织会议暨2013中国纺织学术年会 时间:2013年10月24-26日 地点:上海东华大学 分会场:新一代聚酯材料 报告题目:玻璃态聚酯纤维在牵伸过程中结晶及取向的研究 报告人:王幼江
报告英文简介: Mechanical drawing of poly(ethylene terephthalate) (PET) fibers is necessary to enhance the fiber mechanical properties by increasing their crystallinity and molecular orientation. On the other hand, the draw ratio for PET fibers is limited due to the development of crystallinity in the polymer. In contrast, under the superdrawing conditions, amorphous PET may undergo very large elongational deformation without developing significant crystallization and molecular orientation. Exploiting the superdrawing phenomenon may lead to novel processes and products. A comprehensive experimental study was conducted to determine the conditions for amorphous PET fibers to develop crystallinity and orientation, especially the effect of strain rate and temperature. Drawing experiments were carried out at temperatures from 90°C to 120°C and at strain rates ranging from 0.008/s to 0.425/s. Crystallinity and orientation of the drawn samples were evaluated using differential scanning calorimetry (DSC) and birefringence measurements. Previous studies reported in the literature suggest that crystallization in PET may be avoided if the drawing strain rate is low enough to allow chain relaxation. Our study, however, indicated that at relatively high temperatures, crystallization was likely to occur if the strain rate is low, whereas at relatively low drawing temperatures, crystallization was likely to occur if the strain rate is high. This phenomenon is a result of two competing mechanisms, namely strain induced crystallization and thermal crystallization, both functions of temperature.
【专题】第十二届亚洲纺织会议暨2013中国纺织学术年会 http://www.ctei.gov.cn/special/2013nzt/atc12/
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