Small-angle X-ray scattering from polyethylene: Distorted lamellar structures
Small-angle X-ray scattering from polyethylene: Distorted lamellar structures
复制标题
聚乙烯的小角 X 射线散射：扭曲的层状结构
DOI：
10.1002/app.12890
复制
发表时间：
2003
影响因子：
3
通讯作者：
V. Causin
中科院分区：
文献类型：
--
作者：
C. Marega;A. Marigo;V. Causin
文中描述了一些理论模型，包括第二类薄层扭曲。为了验证片层扭曲对聚合物小角X射线散射(SAXS)的影响，计算了不同模型参数下的一些理论图样。记录了三个含有不同共聚单体的线性低密度聚乙烯商业共聚样品和一个高密度聚乙烯商业均聚物样品的SAXS衍射谱，并与我们的理论模型相对应的计算轮廓进行了拟合分析。用透射电子显微镜观察了四种样品的片层形貌。由此我们得出结论，均聚物样品在片层堆栈上表现出良好的组织结构，而共聚物样品表现出更多不完美的片层形态，因此在后者的情况下，在计算的SAXS衍射图中引入扭曲的片层结构是有用的。通过广角X射线散射，我们还测定了样品的总结晶度。©2003威利期刊公司应用多维科学杂志90：2400-2407,2003
Some theoretical models, including lamellar distortions of the second kind, are described. To test the influence of lamellar distortions on the small-angle X-ray scattering (SAXS) of polymers, some theoretical patterns were calculated with different values of the model parameters. SAXS diffraction profiles were recorded for three commercial copolymer samples of linear low-density polyethylene containing different comonomers and one commercial homopolymer sample of high-density polyethylene; these were successively analyzed by a fit to the calculated profiles corresponding to our theoretical models. Transmission electron microscopy images were obtained of the lamellar morphologies of the four samples. From these, we concluded that the homopolymer sample displayed excellent organization on lamellar stacks, whereas the copolymer samples showed more imperfect lamellar morphologies, so it was useful, in the latter case, to introduce a distorted lamellar structure in calculated SAXS diffraction patterns. By use of wide-angle X-ray scattering, we also determined the overall crystallinities of the samples. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2400–2407, 2003