论文标题
聚合物的最佳纠缠促进了高度定向纤维的形成
Optimal Entanglement of Polymers Promotes Formation of Highly Oriented Fibers
论文作者
论文摘要
聚合物纤维由沿纤维轴定向的大分子组成。更好的链条对齐会导致纤维的强度提高。据认为，防止形成完全定向纤维的关键因素是聚合物的纠缠。我们进行了半晶体超高分子量聚乙烯单轴拉伸的大规模计算机模拟。我们发现，在纤维中最大化链方向所需的每个大分子的纠缠数量最佳。纠缠太强的聚合物的定向纤维较少。另一方面，当聚合物每个链中的纠缠太少时，它们在拉伸过程中散布，并且没有形成强纤维。我们构建了描述纤维形成和分离过程的微观分析理论。我们的工作对纤维生产过程中纠缠的作用提出了一种新的看法，并预测了每个链条的单一通用最佳纠缠数量，使纤维质量最大化：约$ 10^2 $纠缠。
Polymer fibers consist of macromolecules oriented along the fiber axis. Better alignment of chains leads to an increased strength of the fiber. It is believed that the key factor preventing formation of a perfectly oriented fiber is entanglement of polymers. We performed large-scale computer simulations of uniaxial stretching of semicrystalline ultrahigh molecular weight polyethylene. We discovered that there is an optimal number of entanglements per macromolecule necessary to maximize chain orientation in a fiber. Polymers that were entangled too strongly formed less oriented fibers. On the other hand, when polymers had too few entanglements per chain, they disentangled during stretching, and the strong fiber was not formed. We constructed a microscopic analytical theory describing both the fiber formation and disentanglement processes. Our work presents a novel view on the role of entanglements during fiber production and predicts the existence of a single universal optimal number of entanglements per chain maximizing the fiber quality: approximately $10^2$ entanglements.
