A highly ordered m-phenylenediimino-bridged ladder polyhydrosiloxane （abbr. OLPHS） with Mn = 1.24 × 10^4 was synthesized stoichiometric hydrolysis and dehydrochlorination condensation reaction between Si-Cl and...A highly ordered m-phenylenediimino-bridged ladder polyhydrosiloxane （abbr. OLPHS） with Mn = 1.24 × 10^4 was synthesized stoichiometric hydrolysis and dehydrochlorination condensation reaction between Si-Cl and Si-OH bonds. The complete ladder structure of OLPHS has been confirmed by the following three data. Two characteristic Bragg＇s peaks representing the ladder width （w = 0.94 nm） and ladder thickness （t = 0.42 nm） were observed in XRD analysis, which are consistent with those calculated by molecular simulation. The very sharp absorption with a small half-peak width （w1/2 = 0.5 ppm） for [（-HN）HSiO2/2]n moiety of OLPHS in ^29Si NMR spectrum indicated presence of the complete ladder structure. As collateral evidence, a higher glass transition temperature （Tg = 105 ℃） is also recorded in the DSC measurement, implying the high stiffness of ladder chain of OLPHS.展开更多
A novel, reactive amide-bridged ladder polyvinylsiloxane （abbr. LP） with Mn= 2.4×10^4 was synthesized for the first time by means of aryl amide H-bonding self-assembled template. The regularity of LP was charac...A novel, reactive amide-bridged ladder polyvinylsiloxane （abbr. LP） with Mn= 2.4×10^4 was synthesized for the first time by means of aryl amide H-bonding self-assembled template. The regularity of LP was characterized by the XRD, ^29Si NMR and DSC methods. XRD analysis demonstrated the ladder width w = 9.09A and the ladder thickness t = 3.89A, respectively, which are approximately consistent with the molecular simulation-calculated ones： w＇= 10.60A and t＇= 3.06A. ^29Si NMR displayed a resonance peak with small half peak width, △1/2 - 4 ppm, for the moiety [=Si（Vi）O2/2-]n of LP. Besides, as a collateral evidence, DSC measurement revealed a high glass transition temperature Tg = 225℃, suggesting high stiffness of the ladder main chain of LP.展开更多
文摘A highly ordered m-phenylenediimino-bridged ladder polyhydrosiloxane （abbr. OLPHS） with Mn = 1.24 × 10^4 was synthesized stoichiometric hydrolysis and dehydrochlorination condensation reaction between Si-Cl and Si-OH bonds. The complete ladder structure of OLPHS has been confirmed by the following three data. Two characteristic Bragg＇s peaks representing the ladder width （w = 0.94 nm） and ladder thickness （t = 0.42 nm） were observed in XRD analysis, which are consistent with those calculated by molecular simulation. The very sharp absorption with a small half-peak width （w1/2 = 0.5 ppm） for [（-HN）HSiO2/2]n moiety of OLPHS in ^29Si NMR spectrum indicated presence of the complete ladder structure. As collateral evidence, a higher glass transition temperature （Tg = 105 ℃） is also recorded in the DSC measurement, implying the high stiffness of ladder chain of OLPHS.
文摘A novel, reactive amide-bridged ladder polyvinylsiloxane （abbr. LP） with Mn= 2.4×10^4 was synthesized for the first time by means of aryl amide H-bonding self-assembled template. The regularity of LP was characterized by the XRD, ^29Si NMR and DSC methods. XRD analysis demonstrated the ladder width w = 9.09A and the ladder thickness t = 3.89A, respectively, which are approximately consistent with the molecular simulation-calculated ones： w＇= 10.60A and t＇= 3.06A. ^29Si NMR displayed a resonance peak with small half peak width, △1/2 - 4 ppm, for the moiety [=Si（Vi）O2/2-]n of LP. Besides, as a collateral evidence, DSC measurement revealed a high glass transition temperature Tg = 225℃, suggesting high stiffness of the ladder main chain of LP.
