Biaxial Stretching of Ultra-High Strength Polyolefin Gel Films

本项目主要研究超高分子量聚烯烃凝胶膜的双轴拉伸，特别是超高分子量聚乙烯和超高分子量聚丙烯。单轴拉伸UHMWPE凝胶显示出与钢或凯夫拉尔纤维等同类产品相当的超高强度。然而，这种单轴驱动的纤维在横向上由于纤颤而固有地弱。通过在凝胶中引入双轴取向，可以显著提高凝胶的侧向强度。PI将在双轴拉伸之前对超高分子量聚乙烯凝胶进行交叉轧制，以限制双轴拉伸期间样品厚度的显着减少。另一个要解决的领域是通过探测标记分子来研究凝胶绘图的机制。第三个领域是通过传统的时间分辨光散射、SAXS、WAXD和光学显微镜研究超高分子量聚乙烯凝胶的熔化和结晶行为以及凝胶球粒的变形机制。

The project deals with the study of biaxial stretching of ultra- high molecular weight polyolefin gel films, especially UHMWPE and UHMWPP. Uniaxially drawn UHMWPE gels have shown ultra-high strength comparable to its counterparts such as steel or KevlarR fibers. However, such uniaxially driven fibers are inherently weak in transverse direction due to fibrillation. The lateral strength may be significantly improved by introducing biaxial orientation in the gels. The PI will perform cross-rolling of UHMWPE gels prior to biaxial stretching to limit significant reduction of sample thickness during biaxial stretching. Another area that will be addressed is to study the mechanisms of gel drawing by probing labelled molecules. A third area that will be addressed is a study of melting and crystallization behavior of UHMWPE gels and the deformation mechanisms of gel spherulites by conventional time-resolved light scattering, SAXS, WAXD and optical microscopy.