Effects of high molecular weight component on crystallization of polyethylene under shear flow
Effects of high molecular weight component on crystallization of polyethylene under shear flow
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DOI：
10.1016/j.polymer.2005.08.102
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发表时间：
2006-07-12
期刊：
影响因子：
4.6
通讯作者：
Kanaya, T.
中科院分区：
文献类型：
--
作者：
Ogino, Y.;Fukushima, H.;Kanaya, T.
用时间分辨去偏振光散射(DPLS)法研究了剪切流动条件下低相对分子质量组分和高相对分子质量组分共混物的结晶行为，重点研究了高相对分子质量组分对烤肉串结构形成的影响。在一定浓度的高相对分子质量PE上，观察到由于类Shish结构的形成而产生的各向异性二维散射图。阈值大约是链重叠浓度的2.5-3倍，这表明高分子量组分的纠缠起着重要作用。在这些结果的基础上，提出了凝胶纺丝形成类Shish结构的机理。DPLS结果还表明，类Shish结构主要由高相对分子质量的PE形成。小角中子散射(SANS)和小角X射线散射(SAXS)测量证实了这一点。(C)2006爱思唯尔有限公司。保留所有权利。
Crystallization of polyethylene (PE) blends of low and high molecular weight components under shear flow was studied using time-resolved depolarized light scattering (DPLS), focusing on effects of the high molecular weight component on the shish-kebab structure formation. Anisotropic two-dimensional scattering pattern due to shish-like structure formation was observed above a certain concentration of the high molecular weight PE. The threshold was about 2.5-3 times larger than the chain overlap concentration, suggesting an important role of entanglements of the high molecular weight component. On the basis of these results a gel-spinning-like mechanism for the shish-like structure formation has been proposed. The DPLS results also implied that the shish-like structure was mainly formed from the high molecular weight PE. This was confirmed by small-angle neutron scattering (SANS) and small-angle X-ray scattering (SAXS) measurements on an elongated PE blend of low molecular weight deuterated PE and high molecular weight hydrogenated PE (3 wt%). (c) 2006 Elsevier Ltd. All rights reserved.