US-Egypt Cooperative Research: Processing Techniques for Improving Mechanical Properties of Biodegradable Polymers

0111334Mark描述：该奖项是为了支持詹姆斯E。Mark，辛辛那提大学化学系，俄亥俄州辛辛那提和Mohammed Sharaf博士，埃及开罗赫勒万大学化学系。 他们计划设计新技术，将聚合物链加工成高性能材料。 具体而言，他们计划：确定具有足够刚度的聚合物链，以产生液晶各向异性相，由刚性和柔性序列组成的均聚物或嵌段共聚物，在溶剂存在下通过过氧化物热处理、化学试剂或高能辐射交联链。 交联赋予聚合物足够的坚固性以保持在变形状态任何时间长度，并且溶剂防止刚性链的过早有序化，使溶胀网络单轴或双轴变形以诱导链段取向，并且以恒定长度或恒定力除去溶剂，引起一级转变，从而产生单相、均匀和高度有序的材料。 这些技术将应用于具有所需生物降解性水平的聚合物。 这种分子有序的控制将同时用于优化机械性能和环境降解性。范围：该项目支持两个著名科学家之间的合作，他们具有互补的专业知识和资源，以调查一个重要的材料和环境问题。 他们过去的合作是富有成效的。 该项目结合了PI的优势，以及与聚合物分子取向和强度相关的问题，以及与可生物降解聚合物相关的挑战。 将有机会与埃及的工业科学家进行互动，以测试这种合作的影响。 两名美国研究生将参与该项目。 该项目符合INT的目标，即支持在共同感兴趣的领域进行合作研究。

0111334MarkDescription: This award is to support a collaborative project between Dr. James E. Mark, Department of Chemistry, University of Cincinnati, Cincinnati, Ohio and Dr. Mohammed Sharaf, Department of Chemistry, Helwan University, Helwan, Cairo, Egypt. They plan to devise new techniques for processing polymer chains into high-performance materials. Specifically they plan to: identify polymeric chains of sufficient stiffness to give liquid-crystalline, anisotropic phases, either homopolymers or block copolymers consisting of stiff and flexible sequences, cross-linking the chains, either by peroxide thermolysis, chemical regents, or high-energy radiation, in the presence of solvent. The cross links confer sufficient solidity for the polymer to remain in a deformed state for any length of time, and the solvent prevents the premature ordering of the stiff chains, deforming the swollen network uniaxially or biaxially to induce segmental orientation, and removing the solvent, at constant length or at constant force, causing a first-order transition, and thus yielding a single-phase, homogeneous, and highly ordered material. These techniques will be applied to polymers having a desired level of biodegradability. This control of molecular ordering will be used simultaneously to optimize mechanical properties and environmental degradability.Scope: The project supports collaboration between two well-known scientists who have complementary expertise and resources to investigate an important material and environmental problem. Their past collaboration has been productive. The project is a combination of strengths of the PIs, and issues related to molecular orientation and strength in polymers with the challenges associated with biodegradable polymers. There will be opportunities for interaction with industrial scientists in Egypt to test the impact of this collaboration. Two US graduate students will participate in the project. This project meets the INT objective of supporting collaborative research in areas of mutual interest.