Nanocomposites from nanoscale silica particles（NS）,diglycidylether of bisphenol-A based epoxy（DGEBA）,and 3,5-diamino-N-（4-（quinolin-8-yloxy） phenyl） benzamide（DQPB） as curing agent were obtained from direct ...Nanocomposites from nanoscale silica particles（NS）,diglycidylether of bisphenol-A based epoxy（DGEBA）,and 3,5-diamino-N-（4-（quinolin-8-yloxy） phenyl） benzamide（DQPB） as curing agent were obtained from direct blending of these materials.The effect of nanosilica（NS） particles as catalyst on the cure reaction of DGEBA/DQPB system was studied by using non-isothermal DSC technique.The activation energy（E_a） was obtained by using Kissinger and Ozawa equations. The E_a value of curing of DGEBA/DQPB/10%NS system showed a decrease of about 10 kJ/mol indicating the catalytic effect of NS particles on the cure reaction.The E_a values of thermal degradation of the cured samples of both systems were 148 kJ/mol and 160 kJ/mol,respectively.The addition of 10%of NS to the curing mixture did not have much effect on the initial decomposition temperature（T_i） but increased the char residues from 20%to 28%at 650℃.展开更多
The effects of cure temperature history on the stability of hinged structure poly（4,4-oxydiphenylene pyromellitimide）（PMDA-ODA） polyimide were studied by dynamic mechanical analysis.The polyimide films were cured ...The effects of cure temperature history on the stability of hinged structure poly（4,4-oxydiphenylene pyromellitimide）（PMDA-ODA） polyimide were studied by dynamic mechanical analysis.The polyimide films were cured under different curing conditions and peeled off by substrate etching.It was found that a proper cure time and temperature ramp rate improves the stability in terms of higher glass transition temperature.Ninety minutes at 375℃or 200℃is a beneficial high glass transition temperature.The temperature ramp rate should be between 2℃/min and 10℃/min,which is neither too high nor too low.展开更多
文摘Nanocomposites from nanoscale silica particles（NS）,diglycidylether of bisphenol-A based epoxy（DGEBA）,and 3,5-diamino-N-（4-（quinolin-8-yloxy） phenyl） benzamide（DQPB） as curing agent were obtained from direct blending of these materials.The effect of nanosilica（NS） particles as catalyst on the cure reaction of DGEBA/DQPB system was studied by using non-isothermal DSC technique.The activation energy（E_a） was obtained by using Kissinger and Ozawa equations. The E_a value of curing of DGEBA/DQPB/10%NS system showed a decrease of about 10 kJ/mol indicating the catalytic effect of NS particles on the cure reaction.The E_a values of thermal degradation of the cured samples of both systems were 148 kJ/mol and 160 kJ/mol,respectively.The addition of 10%of NS to the curing mixture did not have much effect on the initial decomposition temperature（T_i） but increased the char residues from 20%to 28%at 650℃.
基金supported by the National Science and Technology Major Project(No.2009ZX02025-1)
文摘The effects of cure temperature history on the stability of hinged structure poly（4,4-oxydiphenylene pyromellitimide）（PMDA-ODA） polyimide were studied by dynamic mechanical analysis.The polyimide films were cured under different curing conditions and peeled off by substrate etching.It was found that a proper cure time and temperature ramp rate improves the stability in terms of higher glass transition temperature.Ninety minutes at 375℃or 200℃is a beneficial high glass transition temperature.The temperature ramp rate should be between 2℃/min and 10℃/min,which is neither too high nor too low.
