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

0111334MarkDescription：该奖项是为了支持俄亥俄州辛辛那提大学化学系James E.Mark博士和埃及开罗Helwan大学Helwan大学化学系Mohammed Sharaf博士之间的合作项目。他们计划设计新的技术，将聚合物链加工成高性能材料。具体地说，他们计划：确定具有足够刚性的聚合链，以产生液晶、各向异性相，无论是均聚物还是由刚性和柔性序列组成的嵌段共聚物，通过过氧化氢热解、化学试剂或在溶剂存在下的高能辐射使链交联。交联物赋予聚合物足够的坚固性，使其在任何时间内保持变形状态，并且溶剂防止刚性链的过早有序化，使膨胀的网络单轴或双轴变形以诱导链段取向，并在恒定长度或恒定力下去除溶剂，导致一级转变，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期望水平的生物降解性的聚合物。这种对分子有序性的控制将同时用于优化机械性能和环境降解性。范围：该项目支持两位拥有互补专业知识和资源的知名科学家之间的合作，以研究重要的材料和环境问题。他们过去的合作卓有成效。该项目结合了PI的优势，以及与聚合物中的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。该项目符合支持共同感兴趣领域的合作研究的INT目标。

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.