Curing behavior of a model epoxies system (E-54/AG-80) with DDS as hardener was studied in this paper. Round disk compression mode DMA was executed to study the gel behaviors at different temperatures to determine the...Curing behavior of a model epoxies system (E-54/AG-80) with DDS as hardener was studied in this paper. Round disk compression mode DMA was executed to study the gel behaviors at different temperatures to determine the relationship between gel-time (t_ gel) and temperature. The cure kinetics was studied by dynamic DSC analysis. Parameters were obtained for establishing a phenomenological cure reaction model. The relationship between glass transition temperature (T_g) and cure degree (α) was also analyzed by both isothermal and dynamic DSC method based on DiBenedetto equation, which gave a mathematical description of T_g as a function of both time and temperature. Consequently, characteristic temperatures such as T_ g0, gelT_ g and T_ g∞ were determined. Finally, the Time-Temperature-Transition (TTT) diagram was designed based on the data and equations.展开更多
This article uses a 2/4 functional epoxy blend system （E-54/AG-80） cured with diaminodiphenyl sulphone（DDS） as a raw material and develops a methodological procedure to establish a cure kinetic model with isotherm...This article uses a 2/4 functional epoxy blend system （E-54/AG-80） cured with diaminodiphenyl sulphone（DDS） as a raw material and develops a methodological procedure to establish a cure kinetic model with isothermal and dynamic differential scanning calorimeter（DSC） method and a gelation model with round-disk compression mode dynamic mechanical analyzer（DMA）, thus acquiring a series of experimental data. Characteristic temperatures such as initial glass transition temperature Tg0, gelation glass transition temperature gelTg, and infinite glass transition temperature Tg∞ are determined. The cure degree at gelation is turned out to be 0.45, while ge1Tg is found to be 70.2 ℃. The data are then used to form time-temperature-transition（TTT） diagram of the system, which serves to be a tool for process optimization of epoxy-matrix composites. A new cure processing is therefore derived from the TTT diagram. The final phase structure obtained from a controllable method is identified through scanning electron microscope（SEM） photographs to be of＂ex-situ＂ phase morphology.展开更多
Time-temperature-transformation diagram for epoxy-terminated poly(phenylene ether ketone) and 4, 4*-diaminodiphenyl sulfone was studied using a differential scanning calorimeter, thermal grametry analyzer and a cone-a...Time-temperature-transformation diagram for epoxy-terminated poly(phenylene ether ketone) and 4, 4*-diaminodiphenyl sulfone was studied using a differential scanning calorimeter, thermal grametry analyzer and a cone-and-plate rheometer. Based on a predicting model proposed here, which is used for determining the times to vitrification (tvit), and only few experimental results from DSC, T’GA and cone-and-plate rileometer, TTT diagram can be easily determined.展开更多
文摘Curing behavior of a model epoxies system (E-54/AG-80) with DDS as hardener was studied in this paper. Round disk compression mode DMA was executed to study the gel behaviors at different temperatures to determine the relationship between gel-time (t_ gel) and temperature. The cure kinetics was studied by dynamic DSC analysis. Parameters were obtained for establishing a phenomenological cure reaction model. The relationship between glass transition temperature (T_g) and cure degree (α) was also analyzed by both isothermal and dynamic DSC method based on DiBenedetto equation, which gave a mathematical description of T_g as a function of both time and temperature. Consequently, characteristic temperatures such as T_ g0, gelT_ g and T_ g∞ were determined. Finally, the Time-Temperature-Transition (TTT) diagram was designed based on the data and equations.
基金National Basic Research Program of China (2003CB615604)
文摘This article uses a 2/4 functional epoxy blend system （E-54/AG-80） cured with diaminodiphenyl sulphone（DDS） as a raw material and develops a methodological procedure to establish a cure kinetic model with isothermal and dynamic differential scanning calorimeter（DSC） method and a gelation model with round-disk compression mode dynamic mechanical analyzer（DMA）, thus acquiring a series of experimental data. Characteristic temperatures such as initial glass transition temperature Tg0, gelation glass transition temperature gelTg, and infinite glass transition temperature Tg∞ are determined. The cure degree at gelation is turned out to be 0.45, while ge1Tg is found to be 70.2 ℃. The data are then used to form time-temperature-transition（TTT） diagram of the system, which serves to be a tool for process optimization of epoxy-matrix composites. A new cure processing is therefore derived from the TTT diagram. The final phase structure obtained from a controllable method is identified through scanning electron microscope（SEM） photographs to be of＂ex-situ＂ phase morphology.
文摘Time-temperature-transformation diagram for epoxy-terminated poly(phenylene ether ketone) and 4, 4*-diaminodiphenyl sulfone was studied using a differential scanning calorimeter, thermal grametry analyzer and a cone-and-plate rheometer. Based on a predicting model proposed here, which is used for determining the times to vitrification (tvit), and only few experimental results from DSC, T’GA and cone-and-plate rileometer, TTT diagram can be easily determined.
