Environmental Dependency of Weak Attractive Interactions of Polymers and Their Applications to Molecular Design of Polymers

(1)聚乙烯亚胺的溶液性质通过对聚乙烯亚胺（PEI）的光散射（LS）实验，确定了聚乙烯亚胺（PEI）的θ条件，并对其无扰动链尺寸进行了评价。PEI的样品制备方法适用于LS的测量：将前驱体聚合物水解后，用氨水中和残留的盐酸，然后通过透析和分馏纯化得到PEI。从乙醇溶液中得到了明确的Zimm图，但数据表明PEI链即使在稀溶液中也聚集。我们将继续寻找θ条件，例如，在水溶液中加入无机盐，并分析乙醇溶液中形成的聚集体结构。(2)通过从头算分子轨道（MO）计算，在三维周期边界条件下，对无水、0.5- 1.5-和2.0-水质子交换体的晶体结构进行了优化。本文成功地确定了三种聚硒醚的晶体结构，并对其电子结构、电子性质和光学性质进行了预测。(3)聚硒醚的构象分析通过与相关聚醚和聚硫化物的比较，阐明并讨论了聚亚硒醚、聚硒醚和聚三亚硒醚的构象特征，并对其晶体结构和物理性质进行了表征；也就是说，从初级结构中预测了高级结构和物理性质。(4)对具有不同杂原子构象、二级结构和晶体结构的聚（乙烯亚胺-乙基环氧乙烷）、聚（乙烯亚胺-乙基硫化乙烯）和聚（乙烯环氧乙烷-乙基硫化乙烯）聚合物进行了预测和表征，并利用原子动力学计算和旋转异构态方案进行了预测和表征。以上(3)和目前的研究为聚合物的分子设计提供了实际的例子。少

(1) Solution properties of poly (ethylene imine) Light scattering (LS) experiments on poly (ethylene imine) (PEI) have been conducted to find the theta conditions and to evaluate the unperturbed chain dimension. The sample preparation of PEI has been adapted for the LS measurements: after hydrolysis of the precursor polymer, the residual hydrochloric acid was neutralized with ammonia, and PEI thus obtained was purified by dialysis and fractionated. Well-defined Zimm plots were obtained from the ethanol solutions, but the data indicate that PEI chains are aggregated even in dilute solutions. We will continue to search for the theta renditions, for example, by adding inorganic salt (s) into the aqueous solution and analyze the aggregate structure formed in the ethanol solutions.(2) Crystal structure determination by the ab initio molecular orbital (MO) calculations Crystal structures of anhydrous and 0.5- 1.5-, and 2.0-hydrous PEIs have been optimized by ab initio MO calculations with di … More fferent theories and basis sets under three-dimensional periodic boundary conditions. For three polyselenoethers to be mentioned below, the crystal structures were successfully determined, and their electronic structures, electronic properties, and optical properties were predicted.(3) Conformational analysis of polyselenoethers Conformational characteristics of poly (methylene selenide), poly (ethylene selenide), and poly (trimethylene selenide) have been elucidated and discussed by comparison with those of related polyethers and polysulfides, and their crystal structures and physical properties were also characterized; that is, the higher structures and physical properties were predicted from the primary structures.(4) Prediction and characterization of polymers with different heteroatoms Conformations, secondary structures, and crystal structures of poly (ethylene imine-alt-ethylene oxide), poly (ethylene imine-alt-ethylene sulfide), and poly (ethylene oxide-alt-ethylene sulfide) have been predicted and well characterized by abinitio MO calculations and the rotational isomeric state scheme. The above (3) and present studies have afforded actual examples of molecular design for polymers. Less