Micro-Macro Scale Relationship in Creep Deformation of Ultra High Molecular Weight Polyethylene
Micro-Macro Scale Relationship in Creep Deformation of Ultra High Molecular Weight Polyethylene
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DOI：
10.1007/s10118-021-2628-6
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发表时间：
2021-08
影响因子：
4.3
通讯作者：
Bijin Xiong;Zhenxian Chen;Jian Kang
中科院分区：
文献类型：
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作者：
Bijin Xiong;Zhenxian Chen;Jian Kang
用SAXS研究了超高相对分子质量聚乙烯的宏观和微观蠕变变形。提出了一种测量片层间非晶相局部蠕变变形的方法。计算了片层间非晶相的局部应变(εa)和宏观应变(ε宏)，并将它们进行比较，以研究超高相对分子质量聚乙烯宏观和微观蠕变变形之间的关系。随着蠕变时间的延长，两者都呈现出两个变形区。纠缠对宏观和局部层间非晶相的蠕变行为都有很大的影响，并且可以很好地与由应变硬化模数估计的两个纠缠之间的分子量相关联。与宏观蠕变相比，局部层间非晶层的蠕变变形较小。根据局部蠕变测量，还可以估算出片层间非晶相的表观模数(200<；mA<；500 Mpa)。这些值远高于块体非晶态PE的杨氏模数，这可以很好地解释为片层堆栈的限制和纠缠浓度相对较高的非晶相的增强。该研究为粘弹性变形研究提供了实现微观和宏观结构尺度转换的有效手段和定量数据。
Macroscopic and microscale creep deformations of UHMWPE were investigated by usingin situSAXS. A methodology for the measurement of the local creep deformation of inter-lamellar amorphous phase has been proposed. The local strain of inter-lamellar amorphous phase (εa) and macroscopic strain (εmacro) were evaluated and they were compared to study the relationship between macroscopic and microscale creep deformation of UHMWPE. Both of them exhibit two deformation regions against creep time. The entanglements show a strong impact on both the macroscopic and local inter-lamellar amorphous phase creep behavior and they can be well correlated to the molecular weight between two entanglements estimated from strain-hardening modulus. Compared to the macroscopic creep deformation, local inter-lamellar amorphous layers have a smaller creep deformation. From the local creep measurement, the apparent modulus of inter-lamellar amorphous phase can also be estimated (200 < Ma < 500 MPa). These values are much higher than the Young’s modulus of bulk amorphous PE, which can be well explained by the confinement of the lamellar stacks and the enhancement of the amorphous phase with the relatively high concentration of entanglements. This study provides a useful means and quantitative data for achieving the scale transition between the micro and the macro structural levels for the study of viscos-elastic deformation.