Molecular, Microscopic and Macroscopic Investigation of Fracture in Polymer and Composites

本研究的目的是探讨宏观的， 聚合物断裂的微观和分子方面， 聚合物基复合材料 将特别强调 压力和攻击性的协同效应 环保剂对机械性能的影响高度取向， 超高强度聚合物纤维 债券破裂事件 将采用电子自旋共振（ESR）技术进行监测 在纤维拉伸试验中。 这些实验将提供 关于应力/老化导致的分子变化的信息， 完成最终任务需要打破的链的数量 失败，并深入了解分子机制， 样品失效。 ESR技术也将用于研究 纤维复合材料的失效。 电子自旋共振谱会产生 关于应力分布及其与 复合材料中的纤维失效。

The goal of this research is to explore the macroscopic, microscopic, and molecular aspect of fracture in polymers and polymeric matrix composites. Particular emphasis will be placed on defining the synergistic effects of stress and aggressive environmental agents on mechanical properties of highly oriented, ultra high strength polymeric fibers. The bond rupture events will be monitored with Electron Spin Resonance (ESR) technique during the fiber tensile tests. These experiments will provide information on molecular changes resulting from stress/ageing, the number of chains that need to be broken to accomplish final failure, and insight into the molecular mechanisms active during sample failure. The ESR technique will also be used to study failure of fiber composites. The ESR spectra will yield information on the stress distribution and its relation to the failure of fibers in the composite.