Exploring Molecular Mechanisms for Spurt Flow Instability, Sharkskin-like Surface Melt Fracture and Interfacial Slip

摘要 提案编号：CTS-9632466 负责人：Wang 该项目旨在对线性聚乙烯树脂的熔体破裂和流动不稳定现象有一个基本的了解。 具体来说，提出了实验来揭示喷流行为和鲨鱼皮形成的分子起源。 实验将在受控活塞速度和恒定压力条件下进行。 将研究几何和表面相关现象。 该研究的独特之处在于，熔体流动不稳定性和挤出物分数的主题涉及熔体/壁和熔体/熔体界面处的本体本构特性和流体动力学边界条件之间的高度非线性耦合。 所提出的努力超越了连续体方法，并将尝试与微分子物理学联系起来。 这项研究成果将在聚合物加工工业中具有广泛的适用性。

ABSTRACT Proposal Number: CTS-9632466 Principle investigator: Wang This project is aimed at developing a fundamental understanding of the melt fracture and flow instability phenomena of linear polyethylene resins. Specifically, experiments are proposed to unravel the molecular origin of spurt flow behavior and sharkskin formation. Experiments will be conducted under both controlled piston speed and constant pressure conditions. Geometry and surface dependent phenomena will be studied. The unique feature of the investigation is that the subject of melt flow instability and extrudate fraction involves a highly non-linear coupling between bulk constitutive properties and hydrodynamic boundary conditions at melt/wall and melt/melt interfaces. The proposed effort goes beyond the continuum approach and will attempt to link with micro-molecular physics. The results of this research will have wide applicability in the polymer processing industry.