Intramolecular and Intermolecular Interactions of Polymers with Heteroatoms

(1)分子内多硫化物的相互作用通过核磁共振实验、单体模型化合物的从头算分子轨道（MO）计算和聚合物构型依赖性质的RIS分析，研究了聚（硫化乙烯）和聚（硫化丙烯）在θ状态下的构象特征，并与相应聚醚的构象特征进行了比较。从构型熵和分子间相互作用的角度解释了多硫化物的高熔点。(2)聚乙烯亚胺（PEI）的构象分析通过MO计算和NMR实验对PEI的单体模型化合物N，N'-二甲基乙二胺的构象能进行了评价。计算了PEI的链维作为氢键能的函数。分子间氢键形成的双链螺旋的焓也估计了由MO计算。(3)聚硅的构象分析采用分子动力学模拟的旋转异构状态方案研究了聚（二正丁基硅烷）、聚（二正己基硅烷）和聚（甲基-正丙基硅烷）的构象特征。这样计算的特征比与光散射测定的特征比相当一致。聚硅烷的相变、溶解度和紫外吸收与构象特性成功地联系起来。(4)聚合物液晶模型化合物的构象分析采用热分析、x射线衍射、氘核磁共振等方法研究了低聚物与聚合物液晶模型化合物的结构-性能相关性。利用氘核磁共振研究了辛酸钠- 1-丁醇-水的溶向液晶和向列相液晶中加入的1-丁醇的构象特征。

(1)Intramolecular Interactions of PolysulfidesConformational characteristics of poly(ethylene sulfide) and poly(propylene sulfide) in the theta state have been investigated by NMR experiments and ab initio molecular orbital (MO) calculations for the monomeric model compounds and RIS analysis of configuration-dependent properties of the polymers, and compared with those off the corresponding polyethers. The high melting points of the polysulfides have been elucidated in terms of configuration entropy and intermolecular interactions.(2)Conformational Analysis of Poly(ethylene imine) (PEI)Conformational energies of PEI have been evaluated from MO calculations and NMR experiments for its monomeric model compound, N,N'-dimethylethylenediamine. The chain dimension of PEI was calculated as a function of the hydrogen-bond energy. The enthalpy of the intermolecular hydrogen bond formed in the double-stranded helix was also estimated from MO calculations.(3)Conformational Analysis of PolysilanesConformational characteristics of poly(di-n-butylsilane), poly(di-n-hexylsilane), and poly(methyl-n-propylsilane) have been investigated by a rotational isomeric state scheme with molecular dynamics simulations. Characteristic ratios thus calculated were in fairly good agreement with those determined by light scattering. The phase transition, solubility, and UV absorption of the polysilanes were successfully correlated with the conformational characteristics.(4)Conformational Analysis of Model Compounds of Polymer Liquid CrystalsStructure-property correlations of model compounds of oligomer to polymer liquid crystals have been investigated by thermal analysis, X-ray diffraction, deuterium NMR, etc. Conformational characteristics of 1-butanol incorporated, not only in a lyotropic liquid crystal of sodium octanoate, 1-butanol, and water but also in a nematic liquid crystal have been investigated by deuterium NMR.