Preparation of Polymer Standards with Uniform Molecular Weights and Their Application to the Studies of Polymer Structure and Properties

(1)建立了由自动进样器和六通阀组成的超临界流体色谱仪（SFC）自动分馏系统，以获得均匀的聚合物。利用该SFC系统，成功分离出了等规和间双规聚甲基丙烯酸甲酯（PMMA）、间双规聚苯乙烯、聚异氰酸丁酯、聚异氰酸己酯、聚d -丙交酯和聚l -丙交酯的单体同系物（均匀聚合物）。用核磁共振和质谱分析了均匀聚合物的结构和纯度。(2)确定了均匀等规和间规pmma从13mer到50mer的玻璃化转变温度与分子量的函数关系。当玻璃化转变温度与分子质量的倒数作图时，由自由体积理论导出的线性关系很好地拟合了数据。均匀等规聚甲基丙烯酸甲酯具有较高的结晶度，结晶度高达92%以上。(3)在凝胶渗透色谱（GPC）中，采用具有一定分子量的均匀等规PMMA作为分子量标准，可以准确测定非均匀等规PMMA的分子量分布。均匀聚合物的GPC分析清楚地显示了等规和共规PMMA在水动力体积上的微小差异。(4)在(-)-蒎烯中具有10 ~ 30个重复单元数(n)的均匀聚异氰酸己酯溶液在出现主链n - c键吸收的波长范围内表现出诱导的圆二色性。溶剂减比旋度随温度的升高而降低，随n的增加而单调增加。这些热学性质源于螺旋链结构中过量的单手性。在甲醇溶液中生长了异氰酸丁酯12mer单晶，并用x射线分析确定了晶体结构。(5)通过SFC分馏获得了端功能化的立体规则均匀pmma，并用于构建均匀的聚合物结构，如块状、梳状和星形聚合物。研究了均匀梳状和星形pmmm的溶液性质。少

(1) A Supercritical fluid chromatograph (SFC) equipped with an automatic fractionation system consisting of an automatic injector and six-way valve units was constructed to obtain uniform polymers efficiently. Using this SFC system, the individual homologues (uniform polymers) of isotactic and syndiotactic poly (methyl methacrylate) (PMMA), syndiotactic polystirene, poly (butyl isocyanate), poly(hexyl isocyanate), poly (D-lactide), and poly (L-lactide) were successfully isolated. The structure and purity of uniform polymers were analyzed by NMR and mass spectrometry.(2) The glass transition temperature of uniform isotactic and syndiotactic PMMAs from 13mer to 50mer was determined as a function molecular weight. When the glass transition temperatures were plotted against the reciprocal of molecular weight, the data were well fitted by the linear relationship derived from the free-volume theory. The uniform isotactic PMMAs were highly crystalline, and the degree of crystallinity was foun … More d to exceed 92%.(3) When uniform isotactic PMMAs with definite molecular weights were used as the molecular weight standards in gel permeation chromatography (GPC), the molecular weight distribution of non-uniform isotactic PMMA was able to be determined accurately. A small difference between isotactic and syndiotactic PMMA in hydrodynamic volume was clearly shown by the GPC analysis of uniform polymers.(4) Solutions of uniform poly (hexyl isocyanate) s with numbers of repeating unit (n) from 10 to 30 in (-) -beta-pinene showed induced circular dichroism at the wavelength range where the absorption due to the backbone N-C linkage appears. Solvent-subtracted specific rotation decreased with increasing temperature, and increased monotonously with an increase in n. These chiroptical properties arise from an excess of one-handedness in the helical chain structure. Single crystals were grown from methanol solution of butyl isocyanate 12mer and the crystal structure was determined by X-ray analysis.(5) End-functionalized stereoregular uniform PMMAswere obtained by SFC fractionation and used to construct uniform polymer architectures such as block, comb, and star polymers. Solution properties of the uniform comb nd star PMMs were also investigated. Less