Curing reaction and phase behavior of bismaleimide-polyethersulfone multi-phase system
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摘要: 采用非等温DSC研究了双马来酰亚胺-聚醚砜(BMI-PES)复相树脂体系的固化行为和固化动力学,根据Kissinger方程计算BMI-PES复相树脂固化的表观活化能和指前因子,利用Crane方程计算反应级数,得到反应动力学方程,进行了实验固化度与理论固化度对比验证,通过SEM研究BMI-PES复相树脂微观相结构随固化温度和时间的演化规律。树脂固化行为显示:BMI-PES复相树脂固化反应存在自催化现象,PES参与了BMI固化;随着升温速率增大,BMI-PES复相树脂固化特征温度均向高温移动,但固化热焓基本不变;随着PES添加量增多,反应速率增大,BMI-PES复相树脂固化热焓降低,而峰值固化温度无变化。固化动力学研究表明:随着PES添加量增多,BMI-PES复相树脂固化表观活化能增大,但指前因子和反应级数无变化,固化为一级反应;BMI-PES树脂在200℃固化时,反应前期固化度实验数据与理论值吻合度很高。SEM结果表明,BMI-PES树脂经180℃固化处理后产生了相反转结构。
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关键词:
- 固化动力学 /
- 固化特性 /
- 聚醚砜(PES) /
- 双马来酰亚胺树脂(BMI) /
- 相结构
Abstract: The curing process and curing kinetics of bismaleimide-polyethersulfone (BMI-PES) multi-phase systems were investigated by DSC using the non-isothermal method at different heating rates. The apparent activation energy and the pre-exponential factor of the curing BMI-PES resin systems were calculated by Kissinger method, and the reaction series were computed by means of Crane formula, and the kinetic equation was concluded. The curing reaction kinetics formula of BMI-PES resin was presented and validated with the homologous experiment. The microphase structure evolution of the curing BMI-PES resin systems with the curing temperature as well as curing time was investigated by SEM. The results indicate that autocatalytic phenomenon exists in the curing reaction process of BMI-PES system and PES resin participates in the curing process of BMI resin. With the increasing of the heating rate of BMI-PES, the curing characteristic temperatures of BMI-PES systems shift toward higher temperature values while the curing enthalpy values are almost constant. With the increasing of the PES content, the curing rate increases accordingly, while the enthalpy decreases, and the curing peak temperature is almost constant. Based on the curing kinetics study, the apparent activation energy of BMI-PES curing reaction increases while the pre-exponential factor and the reaction series are not changed. The curing process of the curing reactions follows the first order reaction. The experimental cure degree is fitted highly well with the theoretical one in the initiation of curing reaction at 200℃. The SEM results suggest that phase inversion structure exists in BMI-PES resin system after 180℃.
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