Sterically Congested and Stiffened Alternating Copolymers:  Synthesis, Solution and Solid-State Properties

技术概述功能性芪单体与马来酸酐或马来酰亚胺的交替共聚物是新的空间拥挤、链硬化和精确官能化的大分子。 最近建立的半柔性性质的这些骨干，所产生的空间拥挤的1，2-二苯基基团从芪单体和五元环酐或酰亚胺单元的硬化效果是有趣的光学，表面积，和嵌段共聚物溶液络合行为的起源表现出这些材料。 该项目的研究重点之一是这些半柔性聚合物在有机溶剂（非离子共聚物）和水介质（离子共聚物）中的溶液性质，包括流变学和自组装特性。 将研究新的全阴离子和全阳离子半柔性大分子的小库在各种外部刺激如作为盐浓度和pH下的互穿复合物（IPECs）的性质，并使用动态光散射和其他技术阐明电荷密度、位置和链刚度对IPECs的影响。 此外，电荷密度和电荷类型对新的双亲水性嵌段共聚物的自组装复合物的水溶液行为的影响，含有半柔性交替共聚物嵌段，将被研究。 第二个推力将涉及研究半柔性扭曲交替共聚物结构对聚合物性质如表面积、气体渗透性和固态吸附剂性质的影响。 新的混合嵌段共聚物的基础上聚（亚芳基醚砜）的中间嵌段将与交替的共聚物末端嵌段合成，并将被浇铸成膜的机械，形态和气体渗透性能的研究。 超高交联聚合物颗粒的纳米多孔性质，包含具有选定类型的官能团的半柔性交替结构，将使用氮吸附方法进行研究。非技术概述许多对健康，可持续性，我们社会的安全依赖于新聚合物材料的发现和开发，这些材料使光学和电子领域的各种类型的器件能够功能或可以跨生物膜递送治疗剂的有效载荷。 该基金的基础研究所产生的新聚合物材料在许多领域具有应用潜力，在这些领域中，使聚合物材料成为成功创新产品不可或缺的组成部分。 潜在的应用范围从用于气体如氢气和二氧化碳的吸附剂的高表面积聚合物，具有用于生物医学过程的定制刺激响应性的新型水溶性聚合物，以及用于气体分离的新型混合聚合物膜。 这项研究的结果将在主要会议上发表，并发表在领先的期刊上。 参与该项目的研究生将掌握聚合物科学和工程的基础知识，并将学习在快节奏的跨学科环境中工作。 这些研究生将有机会在弗吉尼亚理工大学的NSF本科生研究体验项目中指导本科生，并与弗吉尼亚理工大学聚合物社区的众多外展项目中的工业研究人员互动。 参与这项研究将为学生提供一个全面的教育平台，为在我国科技型企业中取得成功的职业生涯做好准备

TECHNICAL SUMMARYAlternating copolymers of functional stilbene monomers with maleic anhydride or maleimides are new sterically crowded, chain stiffened, and precisely functionalized macromolecules. The recently established semi-flexible nature of these backbones, arising from the steric crowding of the 1,2-diphenyl groups from the stilbene monomers and the stiffening effect of five-member cyclic anhydride or imide units is the origin of interesting optical, surface area, and block copolymer solution complexation behavior exhibited by these materials. One thrust of the research in this project will focus on the solution properties, including rheology and self-assembly characteristics, of these semi-flexible polymers in organic solvents (non-ionic copolymers) and in aqueous media (ionic copolymers). The properties of interpolyelectrolyte complexes (IPECs) of small libraries of new all anionic and all cationic semi-flexible macromolecules under various external stimuli such as salt concentration and pH will be studied and the effect of charge density, placement, and chain stiffness on the IPECs elucidated using dynamic light scattering and other techniques. In addition, the effect of charge density and charge type on the aqueous solution behavior of self assembled complexes of new double hydrophilic block copolymers, containing a semi-flexible alternating copolymer block, will be investigated. A second thrust will involve studies of the effect of the semi-flexible contorted alternating copolymer structures on polymer properties such as surface area, gas permeability, and adsorbent properties in the solid state. New hybrid block copolymers based on poly(arylene ether sulfone) middle blocks will be synthesized with alternating copolymer end blocks and will be cast into films and the mechanical, morphological, and gas permeability properties studied. The nanoporous properties of hypercrosslinked polymer particles, containing semi-flexible alternating structures with selected types of functional groups, will be studied using a nitrogen adsorption method.NON-TECHNICAL SUMMARYMany technologies that are critical for the health, sustainability, and security of our society are dependent on the discovery and development of new polymeric materials that enable various types of devices in the optical and electronic areas to function or that can deliver payloads of therapeutics across biological membranes. The new polymeric materials resulting from the fundamental studies of this grant have potential for applications in a number of areas where enabling polymeric materials are indispensable components in successful innovations to products. Potential applications range from high surface area polymers for adsorbents for gases such as hydrogen and carbon dioxide, new water soluble polymers with tailored stimuli responsiveness for biomedical processes, and new hybrid polymer membranes for gas separations. Results from this research will be presented at major conferences and published in leading journals. Graduate students involved in this project will master the fundamentals of polymer science and engineering and will learn to work in a fast-paced interdisciplinary environment. These graduate students will have the opportunity to mentor undergraduate students in an NSF Research Experience for Undergraduates program at Virginia Tech and interact with industrial researchers in numerous outreach programs from the Virginia Tech polymer community. Participation in this research will provide students with a well-rounded education platform for preparation for successful careers in the science and technology based enterprise of our nation