Dynamics of Precise Ethylene Copolymers and Ionomers Using Dielectric Spectroscopy

技术概述：该项目将探索一类新型聚合物体系的基本动力学：在非常精确间隔的酸（或离子）官能团之间具有单分散乙烯序列的共聚物。受最近合成和自组装聚（乙烯-丙烯酸）[PEAA]精密共聚物和离聚体的启发，本研究将主要利用宽带介电光谱对这些新材料的聚合物和离子动力学进行全面研究。最近的研究结果表明，这些材料比具有随机功能的传统乙烯基共聚物表现出更少的非均质性。更窄的介电弛豫是预期的，使这些理想的模型材料为聚合物动力学的基础研究。高度规则的离子域自组装在离子传输中的作用将被研究，以确定精确的乙烯离聚体是否提供了一条独特的途径，以获得机械坚固，但高导电性的固体聚合物膜。由于相分离微观结构与分子动力学之间有着密切的联系，因此需要对精确的乙烯共聚物和离聚体的纳米级结构有深入的了解。因此，这个项目的一个重要组成部分涉及与其他机构在这些新材料的形态和建模方面的合作。非技术概述：本项目侧重于系统研究一类新的分子精密聚合物材料中的聚合物和离子运动。该研究还将增强对固体聚合物中离子传输的基本理解，对下一代锂离子电池膜、致动器和其他潜在应用感兴趣。乙烯基聚合物具有重要的战略工业意义，是最大的一类商用聚合物。由于该项目是第一个研究精确的乙烯基酸共聚物和离聚体的聚合物和离子运动的项目，它将有助于评估这些新材料的商业潜力。该项目将为研究生和本科生创造学习机会，后者通过高级论文项目或作为宾夕法尼亚州立大学NSF-REU项目的一部分参与软材料。项目参与者将参与外展活动，特别是与宾夕法尼亚州立大学女性科学与工程学院有关的活动。

TECHNICAL SUMMARY:This project will explore the fundamental dynamics of a new class of polymer system: copolymers with monodisperse ethylene sequences between very precisely spaced acid (or ionic) functionalities. Motivated by the recent synthesis and self-assembly of poly(ethylene-acrylic acid) [PEAA] precise copolymers and ionomers this study will focus on the comprehensive investigation of polymer and ion dynamics of these novel materials using primarily broadband dielectric spectroscopy. Recent findings demonstrate that these materials exhibit considerably less heterogeneity than traditional ethylene-based copolymers with randomly placed functionality. Significantly narrower dielectric relaxations are anticipated, making these ideal model materials for the fundamental study of polymer dynamics. The role that highly regular self-assembly of ionic domains has on ion transport will be investigated in order to determine whether precise ethylene ionomers offer a unique route to mechanically robust, yet highly conductive, solid polymer membranes. As there is an intimate connection between phase-separated microstructure and molecular dynamics, a thorough understanding of the nanoscale structure of the precise ethylene copolymers and ionomers is required. Consequently, an important component of this project involves collaborations with other institutions on morphological and moedling aspects of these new materials.NON-TECHNICAL SUMMARY:This project focuses on the systematic investigation of polymer and ion motions in a new class of molecularly precise polymeric materials. The study will also enhance the basic understanding of ion transport in solid polymers, of interest for the next generation of membranes for lithium ion batteries, actuators, and other potential applications. Ethylene-based polymers are of strategic industrial importance, representing the largest class of commercial polymers. As this project is the first to investigate polymer and ion motions of precise ethylene-based acid copolymers and ionomers, it will assist in evaluating the commercial potential of these new materials.The project will create learning opportunities for graduate and undergraduate students, the latter participating through senior thesis projects or as part of the NSF-REU Program at Penn State on soft materials. Program participants will engage in outreach activities, particularly those connected with Penn State's Women in Science and Engineering Institute.