Advantage of Preserving Bi-orientation Structure of Isotactic Polypropylene through Die Drawing
Advantage of Preserving Bi-orientation Structure of Isotactic Polypropylene through Die Drawing
复制标题
模拉保持等规聚丙烯双取向结构的优点
DOI：
10.1007/s10118-020-2465-z
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发表时间：
2021
影响因子：
4.3
通讯作者：
Men Yongfeng
中科院分区：
文献类型：
--
作者：
Lyu Dong;Sun Yingying;Lai Yuqing;Thompson Glen;Caton-Rose Philip;Coates Phil;Lu Ying;Men Yongfeng
等规聚丙烯（iPP）通常具有独特的母子层片结构，其中母子层片以接近垂直的角度彼此相对在加工过程中在iPP中诱导高比例的取向交叉阴影结构对于设计双向取向iPP产品是期望的。结果表明，与自由拉伸相比，模头拉伸工艺在获得高比例的iPP定向交叉影线结构方面具有优势。此外，α-成核剂的存在影响了口模中定向母-子层片的形成，结果表明，由于模具内部的约束变形，模具中的取向交叉线结构得以很好地保留，绘制iPP。
The isotactic polypropylene (iPP) usually shows a unique parent-daughter lamellae structure in which the parent and daughter lamellae are against each other with a near perpendicular angle (80° or 100°).Inducing a high fraction of oriented cross-hatched structure in iPP during processing is desirable for designing the bi-oriented iPP products.We processed a commercial iPP via tensile-stretching and die-drawing to evaluate the structural evolution of oriented parent-daughter lamellae.It turned out that the die-drawing process had an advantage in attaining a high fraction of oriented cross-hatched structure of iPP,as compared to the free tensile stretching.Besides,the presence of α- nucleating agents affected the formation of oriented parent-daughter lamellae in the die-drawn samples whereas such influence diminished in the free stretched ones.It was found that the confined deformation inside the die led to the well-preserved oriented cross-hatched structure in the die-drawn iPP.