Structural evolution of flow-oriented high density polyethylene upon heating: In situ SAXS and WAXD studies
Structural evolution of flow-oriented high density polyethylene upon heating: In situ SAXS and WAXD studies
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流动取向高密度聚乙烯在加热时的结构演变：原位 SAXS 和 WAXD 研究
DOI：
10.1016/j.polymer.2019.121698
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发表时间：
2019-10
期刊：
影响因子：
4.6
通讯作者：
Men Yongfeng
中科院分区：
文献类型：
--
作者：
Liao Tao;Zhao Xintong;Yang Xiao;Coates Phil;Whiteside Ben;Jiang Zhiyong;Men Yongfeng
采用广角X射线衍射（WAXD）和小角X射线散射（SAXS）技术研究了微注射成型高密度聚乙烯（HDPE）在加热过程中分子和片层结构随温度的变化。成型样品表现出一种特殊的多层结构的皮肤和剪切层，并通过存在的shish-kebab样结构的两个群体的层状堆叠的标志。的变化的长周期，以及平均厚度的层状和非晶区域与温度的一维相关函数确定为各自的层状堆叠。利用Ruland方程计算了shish-like结构的平均长度和取向差，结果表明，随着温度的升高，shish-like结构通过自催化过程引入多个部分弛豫链而沿纵向生长.此外，发现结晶相中的链的取向度随着低于100 °C的温度的增加而略微增加，这可以追溯到注射成型后具有低取向度的额外微晶的形成。这些结晶层状结构在二次结晶过程中建立的热稳定性低于初级的，因此在相对较低的温度下退火时选择性地熔化，从而产生分子取向的总体增加。
The structural evolution of micro-injection molded high density polyethylene (HDPE) at the molecular and lamellar levels was investigated as a function of temperature during heating process using wide angle X-ray diffraction (WAXD) and small angle X-ray scattering (SAXS) techniques. The molded sample exhibits a peculiar multilayer structure of skin and shear layers, and is marked by the existence of shish-kebab-like structure with two populations of lamellar stacks. The variations of the long period as well as the average thicknesses of lamellar and amorphous regions with temperature were determined from one-dimensional correlation functions for the respective lamellar stacks. The average length and the misorientation of shish-like formation were calculated using Ruland equation, and the results indicate that the shish-like structure grows in the longitudinal direction with increasing temperature via incorporation of several partially relaxed chains as a result of autocatalytic process. In addition, the degree of orientation of the chains in the crystalline phase was found to increase slightly with increasing temperature below 100 °C, which could be traced back to the formation of additional crystallites with a low degree of orientation after injection molding. These crystalline lamellae built up during the secondary crystallization are less thermally stable than the primary ones, and therefore are melted selectively upon annealing at relatively lower temperatures yielding an overall increase in the molecular orientation.
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影响因子：
3.4
作者：
Mengjue Li;Y. Qi;Zhongguo Zhao;Zhang Xiang;X. Liao;Yanhua Niu;Miqiu Kong
通讯作者：
Mengjue Li;Y. Qi;Zhongguo Zhao;Zhang Xiang;X. Liao;Yanhua Niu;Miqiu Kong
影响因子：
2.4
作者：
A. Pennings;R. Lageveen;R. S. Vries
通讯作者：
A. Pennings;R. Lageveen;R. S. Vries
影响因子：
5.5
作者：
Baijin Zhao;Xiangyang Li;Youju Huang;Yuanhua Cong;Zhe Ma;Chunguang Shao;Haining An;T. Yan;
通讯作者：
Baijin Zhao;Xiangyang Li;Youju Huang;Yuanhua Cong;Zhe Ma;Chunguang Shao;Haining An;T. Yan;
DOI：
10.1007/bf02086621
发表时间：
1970-02
期刊：
Kolloid-Zeitschrift und Zeitschrift für Polymere
影响因子：
--
作者：
A. Pennings;J. Mark;H. C. Booij
通讯作者：
A. Pennings;J. Mark;H. C. Booij
DOI：
10.1016/b978-0-12-440103-7.50009-2
发表时间：
1973
期刊：
Techniques in Protein Chemistry
影响因子：
--
作者：
Ingrid Pilz
通讯作者：
Ingrid Pilz