| Co-Investigator(Kenkyū-buntansha) |
SAITO Muneo JASCO Co., Researcher, 第二技術部, 部長(研究者)
NISHIURA Takafumi Fac.Eng.Sci., Osaka University, Res.Assoc., 基礎工学研究科, 助手 (70243194)
UTE Koichi Fac.Eng.Sci., Osaka University, Assoc.Prof., 基礎工学研究科, 助教授 (30176713)
KITAYAMA Tatsuki Fac.Eng.Sci., Osaka University, Prof., 基礎工学研究科, 教授 (60135671)
|
|---|
| Research Abstract |
(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
|
