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Biphenyl-contained monomer of 1,4-bis[2-(3,4-epoxy cyclohexyl ethyl) dimethylsilyl] biphenyl(BP-Si H-EP) was prepared via hydrosilylation reaction of 1,4-bis(dimethylsilyl) biphenyl(BP-Si H) and 1,2-epoxy-4-vinylcyclohexane in the presence of Karstedt’s catalyst. ~1H-NMR, ~(13)C-NMR and FTIR were used to characterize the structure of the obtained monomer. BP-Si H-EP was then cured by methyl hexahydrophthalic anhydride(Me HHPA) with 1-cyanoethyl-2-ethyl-4-methylimidazole as an accelerator. The polymerization behavior was studied by DSC. The results of DMA measurement demonstrate that the cured BP-Si H-EP/Me HHPA can maintain high storage modulus(>1 GPa) in a wide range of temperature up to 176 °C. According to the damping factor curve of DMA, cured BP-Si H-EP/Me HHPA exhibits a high glass transition temperature(T_g) of 192 ° C, which is 20 ° C higher than that of cured 1,4-bis[2-(3,4-epoxy cyclohexyl ethyl)dimethylsilyl] benzene(DEDSB)/Me HHPA. TGA results show that cured BP-Si H-EP/Me HHPA has good thermal stability(T_(5% )= 339 ° C) due to the high heat-resistance of rigid biphenyl group. Moreover, the crosslinking density of cured BP-Si H-EP/Me HHPA should be lower than that of cured DEDSB/Me HHPA estimated from their chemical structures, which conflicts with the calculated results based on the rubber elasticity equation. The inconsistence indicates that the calculated crosslinking densities are not comparable, possibly owing to their differences in the rigidity of polymer chains and intermolecular interaction.
Biphenyl-contained monomer of 1,4-bis [2- (3,4-epoxy cyclohexyl ethyl) dimethylsilyl] biphenyl (BP-Si H-EP) was prepared via hydrosilylation reaction of 1,4-bis -SiH) and 1,2-epoxy-4-vinylcyclohexane in the presence of Karstedt’s catalyst. ~ 1H-NMR, ~ (13) C-NMR and FTIR were used to characterize the structure of the obtained monomer. BP-Si H The results of DMA measurement demonstrated that the cured BP-Si H (EPP) was then cured by methyl hexahydrophthalic anhydride (Me HHPA) with 1-cyanoethyl-2-ethyl-4-methylimidazole as an accelerator. - EP / Me HHPA can maintain high storage modulus (> 1 GPa) in a wide range of temperature up to 176 ° C. According to the damping factor curve of DMA, cured BP-Si H-EP / Me HHPA exhibits a high glass Transition temperature (T_g) of 192 ° C, which is 20 ° C higher than that of cured 1,4-bis [2- (3,4-epoxy cyclohexyl ethyl) dimethylsilyl] benzene (DEDSB) / Me HHPA. that cured BP-Si H-EP / Me HHPA has good thermal stability (T_ (5%) = 339 ° C) due to the high heat-resistance of rigid biphenyl group. Moreover, the crosslinking density of cured BP-Si H-EP / Me HHPA should be lower than that of inconsistent indicates that the calculated crosslinking densities are not comparable, possibly owing to their differences in the rigidity of polymer chains and intermolecular interaction.