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Energy absorption mechanism of the semi-crystalline polyolefin during the yield process

半晶聚烯烃屈服过程中的能量吸收机理

基本信息

批准号：
18550188
负责人：
NITTA Koh-hei
金额：
$ 2.8万
依托单位：
Kanazawa University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18550188/
关键词：
Rheo-optics Polvole fin Fluorescent Yield process 降伏挙動ラマン分光一軸延伸ポリエチレン

项目摘要

In this study, we mix the fluorescent reagent which does not form the excimer into polyolefines and investigate the fluorescent behavior in the yield region in-situ during uniaxial tensile deformation. We prepare the samples with different crystallinity to reveal the effects of the structural transformation of the crystalline phases on the fluorescent behavior in the yield region.The intensity of fluorescence takes almost constant value before the yield point. The peak intensity suddenly rises up from the yield point and takes the maximum values around the central point between the yield point and the starting point of the neck propagation, so-called secondary yield point at which the neck portion appeared in the center of sample specimen. The peak intensity takes a constant value again during neck propagation. The excess emission of the fluorescence also increases with the crystallinity.The total fluorescent emission linearly increases with the resilience for the HDPE samples and the iPP samples with the crystallinity over 0.5. This result strongly suggests that the origin of the excess fluorescent emission is the release of the storage energy by the fracture of the lamellae at the yield point.

在本研究中，我们将不形成激基缔合物的荧光试剂混入聚烯烃中，原位研究了单轴拉伸变形过程中屈服区的荧光行为。制备了不同结晶度的样品，研究了晶相结构的变化对屈服区荧光行为的影响，发现在屈服点之前，荧光强度基本保持不变。峰值强度从屈服点突然升高，并在屈服点和颈缩扩展起始点之间的中心点周围取最大值，所谓的二次屈服点，在该二次屈服点处颈缩部分出现在试样的中心。在颈部传播期间，峰值强度再次取恒定值。随着结晶度的增加，荧光的过量发射也增加，当结晶度大于0.5时，HDPE和iPP的总荧光发射随回弹性的增加而线性增加。这一结果有力地表明，过量荧光发射的起源是通过在屈服点处的薄片断裂而释放的储存能量。