Functionalized Rigid Polymers

刚性芳族聚酰胺，聚（对亚苯基乙酰胺），PPTA的保留溶解度可以通过向聚合物引入官能团来改善，例如通过将磺酸基团（或其碱性盐）连接到芳族环上，或通过用Aligo（氧杂环丁烷）进行N-取代。磺酸取代的聚酰胺的锂盐或钠盐，PPTS，形成稀释的水性凝胶，其是双折射的，并表现出双折射液晶结构的形态特征。将通过光散射测量和使用数字图像分析的显微镜监测聚集结构的演变来研究这些刚性聚电解质凝胶中的有序-无序转变。这些调查将通过NMR实验来补充，以检测溶液冷却（或凝胶加热）通过过渡区时聚合物弛豫速率的变化。还将确定与转变相关的焓变。刚性凝胶对电刺激的反应是本研究的第二个主题，因为电刺激产生的机械化学和化学阀作用在生物反应中找到了相似之处。还计划研究PPTS或其盐与柔性聚合物的相容性。聚（氧化物）PEO是一个特别有趣的候选人，因为Li-PPTS/PEO/LiClO 4系统显示出足够高的离子电导率，以保证系统的研究。PPTA在N-位上接枝低聚（环氧乙烷）将与PEO、聚（甲基丙烯酸甲酯）或聚（丙烯酸）共混。由于已知PEO可与PMMA混溶并与PAA形成络合物，因此PPTA-g-PEO聚合物可能在分子水平上分散在PEO、PPMA或PAA中。除了使用接枝共聚物来证明这种方法的可行性，分子复合材料，共聚物-PEO系统将作为一个潜在的离子导电材料进行评估。这项研究涉及新的解决方案，凝胶和聚合物混合物作为生物分子材料和离子导体的潜在利益的研究。

The sparing solubility of a rigid aromatic polyamide, poly(p- phenylene terephthalamide), PPTA, can be improved by introducing functional groups to the polymer, for example through the attachment of the sulfonic acid group (or its alkaline salt) to the aromatic ring, or by N-substitution with aligo (oxyethylene). The lithium or sodium salt of the sulfonic acid substituted polyamide, PPTS, form dilute aqueous gels which are birefringent and exhibit morphologies characteristic of nematic liquid crystalline structures. The order-disorder transition in these rigid polyelectrolyte gels will be studied by monitoring the evolution of the aggregated structures by light-scattering measurements and by microscopy using digital image analysis. These investigations will be supplemented by NMR experiments to detect changes in the relaxation rates of the polymer as the solution is cooled (or the gel is Heated) through the transition region. The enthalpy change associated with the transition will also be determined. The response of the rigid polyelectrolyte gels to electric stimulation is the second topic of this study, because the mechanochemical and chemical valve actions produced by electric stimulus find analogies in biological responses. It is also planned to study the miscibility of PPTS or its salts with flexible polymers. Poly(oxyethylene) PEO is a particularly interesting candidate because the Li-PPTS/PEO/LiClO4 system shows sufficiently high ion conductivity to warrant a systematic study. PPTA grafted at the N-position with oligo (oxyethylene) will be blended with PEO, poly(methyl methacrylate) or poly(acrylic acid). Since it is known that PEO is miscible with PMMA and forms complexes with PAA, it is likely that the PPTA-g-PEO polymer can be dispersed on a molecular level in PEO, PPMA, or PAA. Aside from using the graft copolymer to demonstrate the feasibility of this approach to molecular composites, the copolymer-PEO system will be evaluated as a potential ion conducting material. This research involves the study of novel solutions, gels, and polymer mixtures of potential interest as biomolecular materials and ionic conductors.