Deformation-mediated superstructures and cavitation of poly (l-lactide): In-situ small-angle X-ray scattering study
Deformation-mediated superstructures and cavitation of poly (l-lactide): In-situ small-angle X-ray scattering study
复制标题
DOI：
10.1016/j.polymer.2011.12.002
复制
发表时间：
2012-01
期刊：
影响因子：
4.6
通讯作者：
Xiuqin Zhang;K. Schneider;Guoming Liu;Jianhong Chen;K. Brüning;Dujing Wang;M. Stamm
中科院分区：
文献类型：
--
作者：
Xiuqin Zhang;K. Schneider;Guoming Liu;Jianhong Chen;K. Brüning;Dujing Wang;M. Stamm
聚合物在拉伸过程中的空穴化和超结构演化对材料的力学性能有着重要的影响。在这项研究中，我们研究了变形介导的超结构和空化的聚（l-乳酸）（PLA），以及它们对拉伸温度的依赖性，通过原位小角X射线（SAXS）分析加上机械测试。研究发现，在形变过程中，拉伸应力对空泡和晶化变形有很大影响，而拉伸应力与拉伸温度有很大关系。在较低的拉伸温度（70 °C）下，在屈服之前开始空化，然后刺激微晶剪切。而在较高的拉伸温度（90 °C）下，晶粒首先发生剪切，然后结晶变形促进了沿着拉伸方向取向的空洞的形成。较高的拉伸温度有利于形成相对完整的高取向晶体。研究结果为如何通过控制高分子材料在变形过程中的超结构来调节其力学性能提供了基础知识。
Cavitation and superstructure evolution of polymers during stretching play crucial roles to influence the mechanical properties of materials. In this study, we investigated deformation-mediated superstructures and cavitation of poly (l-lactide) (PLA) as well as their dependence on stretching temperatures by in-situ small-angle X-ray (SAXS) analysis coupled with mechanical testing. It is found that the cavitation and crystalline deformation are strongly influenced by stretching stress during deformation, which significantly depends on the stretching temperature. At lower stretching temperature (70 °C), the cavitation is initiated before the yielding and then stimulates the crystallite shearing. At higher stretching temperature (90 °C), however, the crystallites shear firstly and then crystalline deformation promotes the formation of cavities orientated along the stretching direction. High stretching temperature benefits the formation of relatively perfect crystals with high orientation. The results provide the basic knowledge of how to adjust the mechanical properties of polymer materials by controlling their superstructure in the deformation process.