Precise Acid Copolymers and Ionomers: Morphology, Dynamics and Mechanical Properties

技术总结精准酸共聚物是一种新型材料，其官能团沿线性聚乙烯精确均匀分布。例如，可以在每个第9、15或21个碳上放置一个膦酸基。拟议的项目涉及九种精确的酸共聚物和一种具有单基或双基取代的羧酸和膦酸基的无规酸共聚物。这些材料已经建立了合成路线。WINEY对酸性共聚物的形态研究将使用X射线散射、HAADF STEM和电子衍射来确定聚乙烯链段的晶体结构和酸性基团组装的性质。酸性共聚物将与锂、钠、铯和锌中和，形成部分和完全中和的离聚体，Winey将在其中探测离子聚集体的大小、形状、空间排列和组成。众所周知，这些酸性共聚物和离聚体的精确度在形态上具有显著的一致性，使得数据解释和与模拟的比较更加严格。首次研究了三种精密酸共聚物和一种无规酸共聚物及其离聚体的动力学和力学性能。性能测量将包括熔体流变学，探索弹性变形的小应变压缩测试，以及研究塑性变形的大应变循环压缩测试。PI的小组拥有高度专业的专业知识来研究这些非凡的聚合物的形态、动力学和机械性能，这既是先前证明的工作，也是现有的合作。非技术总结PI将研究一组非凡的功能聚合物，最终目标是了解官能团是如何排列的，从而它们的排列如何决定它们的机械性能。这些功能聚合物在聚乙烯分子上的每个第9、15或21个碳原子上都有一个酸基。这些分子前所未有的精确度将导致在微米和纳米尺度上更好的结构有序，这反过来又能够改善分子结构和性质之间的相关性。PI已经与合成化学家、光谱学家和理论家建立了合作，以探索这些非凡的材料，在这个跨学科团队中，更多学生和研究人员的教学、学习和培训将得到极大的丰富。这些精密聚合物是以聚乙烯为基础的，聚乙烯是商业聚合物中最大的一类。该项目涉及这些材料的第一次动力和机械性能测量，并将在这样做的过程中评估它们的商业潜力。

TECHNICAL SUMMARYPrecise acid copolymers are novel materials having functional groups spaced exactly evenly along a linear polyethylene. For example, a phosphonic acid group can be placed on every 9th, 15th or 21st carbon. The proposed project involves nine precise acid copolymers and one random acid copolymer having carboxylic acid and phosphonic acid groups with mono- or geminal-substitution. These materials have established synthetic routes. Winey's morphological studies of the acid copolymers will use X-ray scattering, HAADF STEM, and electron diffraction to establish the crystalline structure of the polyethylene segments and the nature of the acid group assemblies. The acid copolymers will be neutralized with Li, Na, Cs, and Zn to form partially- and fully-neutralized ionomers in which Winey will probe the size, shape, spatial arrangement, and composition of the ionic aggregates. The precision of these acid copolymers and ionomers is known to yield remarkable uniformity in the morphologies, making data interpretation and comparisons with simulations more rigorous. The dynamics and mechanical properties will be studied for the first time in three precise acid copolymers and one random acid copolymer, along with their ionomers. The property measurements will include melt rheology, small-strain compression testing to explore elastic deformations, and large-strain, cyclic compression testing to study plastic deformation. The PI's group has highly specialized expertise to study the morphology, dynamics, and mechanical properties of these remarkable polymers in terms of both demonstrated prior work and existing collaborations. NON-TECHNICAL SUMMARYThe PI will study an extraordinary set of functional polymers with the ultimate goal of knowing how the functional groups are arranged and thereby how their arrangement dictates their mechanical properties. These functional polymers have an acid group on every 9th, 15th or 21st carbon atom along a polyethylene molecule. The unprecedented precision in these molecules will lead to better structural order at both the micro- and nanoscale, which, in turn, enable improved correlations between molecular structure and properties. The PI has established collaborations with synthetic chemists, spectroscopists, and theorists to explore these remarkable materials, and within this interdisciplinary team the teaching, learning, and training of more students and researchers will be significantly enriched. These precise polymers are based on polyethylene, which constitutes the largest class of commercial polymers. This project involves the first dynamical and mechanical property measurements of these materials and in so doing will evaluate their commercial potential.