The reaction mechanism, reactivities, and apparent activation energies of epoxy/dicyanamide curing system accelerated by C6H5NHCONR2 (R=CH3, n-C4H9, i-C3H7,) werestudied by DSC and GC techniques. The results showed th...The reaction mechanism, reactivities, and apparent activation energies of epoxy/dicyanamide curing system accelerated by C6H5NHCONR2 (R=CH3, n-C4H9, i-C3H7,) werestudied by DSC and GC techniques. The results showed that in reaction of C6H5,NHCONR2with either dicyanamide or epoxy resin there was a dimethylamine released reacting with epoxy resin, giving a tertiary amine, which accelerated the anionic homopolymerization of epoxy resin.展开更多
A kind of novel liquid crystalline oxetane monomers containing biphenyl, flexible spacer and cinnamoyl group was synthesized. The monomer was initiated to polymerize by boron trifluoride etherate and resulted in photo...A kind of novel liquid crystalline oxetane monomers containing biphenyl, flexible spacer and cinnamoyl group was synthesized. The monomer was initiated to polymerize by boron trifluoride etherate and resulted in photoreactive polymer, which was highly sensitive to the LPL photochemically. The thermal properties and the mesophase structure of the polymer were investigated by DSC and thermal optical polarized microscope. Three exothermal peaks corresponding to an isotropic-nematic transition, nematic-smectic transition and smectic-crystal transition, respectively, were found on the DSC cooling curve of the polymer. Well-developed fan texture was observed by optical polarizing microscope. The polymer was spin-coated on a SiO-2 glass substrate from DMF solution, resulting in a thin film. Irradiation of a LP-UV light resulted in anisotropic cycloadditions of the cinnamon acyl groups, which caused the alignment of biphenyl groups in side chains at the same time. The differences of absorbance at different irradiation time were obtained which can be used to explain that the polymer can be applied in photoalignment layer.展开更多
文摘The reaction mechanism, reactivities, and apparent activation energies of epoxy/dicyanamide curing system accelerated by C6H5NHCONR2 (R=CH3, n-C4H9, i-C3H7,) werestudied by DSC and GC techniques. The results showed that in reaction of C6H5,NHCONR2with either dicyanamide or epoxy resin there was a dimethylamine released reacting with epoxy resin, giving a tertiary amine, which accelerated the anionic homopolymerization of epoxy resin.
文摘A kind of novel liquid crystalline oxetane monomers containing biphenyl, flexible spacer and cinnamoyl group was synthesized. The monomer was initiated to polymerize by boron trifluoride etherate and resulted in photoreactive polymer, which was highly sensitive to the LPL photochemically. The thermal properties and the mesophase structure of the polymer were investigated by DSC and thermal optical polarized microscope. Three exothermal peaks corresponding to an isotropic-nematic transition, nematic-smectic transition and smectic-crystal transition, respectively, were found on the DSC cooling curve of the polymer. Well-developed fan texture was observed by optical polarizing microscope. The polymer was spin-coated on a SiO-2 glass substrate from DMF solution, resulting in a thin film. Irradiation of a LP-UV light resulted in anisotropic cycloadditions of the cinnamon acyl groups, which caused the alignment of biphenyl groups in side chains at the same time. The differences of absorbance at different irradiation time were obtained which can be used to explain that the polymer can be applied in photoalignment layer.
