Effect of Ions on Polymer Properties: Perfluorinated Ionomers, Model Compounds and Ionomer Blends

拟议研究的目的是研究 离子基团对全氟磺酸结构和动力学的影响 离聚物膜、离聚物溶液和离聚物共混物。 的 计划进行以下实验。 首先，他们将研究 膜中高分子链和反离子的动力学 被极性溶剂溶胀并溶解在极性溶剂中。 的可能性 膜之间过渡的结构变化， 将从研究中推导出溶液作为离聚物的函数 浓度. 实验研究将得到以下补充： 链动力学的理论模型。 第二，他们会 评估基于质子化的反胶束体系的延伸程度 和氟化表面活性剂可以用作模型化合物， 更复杂的全氟化离聚物。 三是 建议研究离聚体中的链段动力学和相结构 混合物，其中特定的相互作用预计将改善 共混物组分的相容性。 我们建议从 聚丙烯酸与无规和嵌段苯乙烯丙烯酸的共混物 与聚（环氧乙烷）和与聚（乙烯基） 吡咯烷酮）。 酸逐渐中和的效果 将研究具有各种抗衡离子的基团。 四是 计划开发电子自旋共振（ESR）成像，作为一种非 研究真实的扩散过程的破坏性方法 时间在离聚物和其他复杂的聚合物系统，在两个和 三维空间 我们建议使用电子病历（包括 多频ESR、双共振和成像）方法 观察顺磁抗衡离子和氘代报告分子 分子，19F NMR观察全氟化链，2H NMR观察全氟化链。 可视化氘代溶剂和DSC的动力学， 宏观性质与局部信息， 光谱测量。 离聚物是两亲聚合物，其含有至多10摩尔 %的离子基团。 有机化合物中离子基团的引入 聚合物是改性聚合物性能的重要方法。 这些基团的存在会导致弹性模量的显著变化， 模量，玻璃化转变温度Tg和渗透率 聚合物中的各种客体，与类似聚合物相比， 没有离子的链。 这些变化大部分归因于 在离聚物中形成相分离形态， 由电荷集中的离子域组成， 主要包括有机骨架的非极性结构域。 这 研究旨在阐明膜的结构。

The objectives of the proposed research is to study the effect of ionic groups on the structure and dynamics of perfluorinated ionomer membranes, ionomer solutions and ionomer blends. The following experiments are planned. FIRST, they will study the dynamics of the polymer chains and counter ions in membranes swollen by, and dissolved in, polar solvents. The possibility of a structural change in the transition between membranes and solutions will be deduced from studies as a function of ionomer concentration. The experimental studies will be complemented by theoretical modeling of the chain dynamics. SECOND, they will assess to what extend reverse micellar systems based on protonated and fluorinated surfactants can be used as model compounds for the more complex perfluorinated ionomers. THIRD, they propose to study segmental dynamics and phase structure in ionomer blends, where specific interactions are expected to improve the miscibility of the blend components. We propose to start with blends of polyacrylic acid and random and block styreneacrylic acid copolymers with poly(ethylene oxide) and with poly(vinyl pyrrolidone). The effect of gradual neutralization of the acid groups with various counter ions will be investigated. FOURTH, we plan to develop electron-spin-resonance (ESR) imaging as a non- destructive method for the study of diffusion processes in real time in ionomers and other complex polymeric systems, in two and three dimensions. We propose to use ESR (including multifrequency ESR, double resonance and imaging) methods for observing the paramagnetic counter ions and deuteriated reporter molecules, 19F NMR to observe the perfluorinated chains, 2H NMR to visualize the dynamics of deuteriated solvents and DSC to correlate the macroscopic properties with the local information obtained from the spectroscopic measurements. Ionomers are amphiphilic polymers that contain up to 10 mole percent of ionic groups. Incorporation of ionic groups in organic polymers is an important method for modifying polymer properties. The presence of these groups causes dramatic changes in the elastic modulus, glass transition temperature Tg and in the permeability of various guests in the polymers, compared to the analogous polymer chains without ions. Most of these changes have been attributed to the formation of a phase-separated morphology in ionomers, consisting of ionic domains where the charges are concentrated, and nonpolar domains that include mainly the organic backbone. This research aims to elucidate the membranes' structure.