酚酞聚芳醚酮-双马来酰亚胺体系流变行为时间-温度依赖性

Time and temperature dependence of rheological behavior for thermal PEKC-BMI composite system

采用流变仪对酚酞聚芳醚酮(PEKC)-双马来酰亚胺(BMI)树脂体系的流变特性的时间和温度依赖性进行了研究,发现:BMI树脂凝胶点对频率有依赖性,而tanδ对频率无依赖性;PEKC-BMI复合树脂体系的黏度增大主要是由于BMI对PEKC的溶解与BMI的热固化。相比较110℃和130℃两种条件,在较高温度时复合树脂体系的黏度增大主要是热固化的影响;随注胶温度提高,复合体系的凝胶时间随PEKC含量的增加而快速缩短,在较高注胶温度下凝胶模量增大较慢,在较低注胶温度下凝胶时模量随PEKC含量的增加而提高较快;随着复合树脂体系中PEKC含量的增加,该体系的凝胶活化能由4.9kJ/mol增大到65.9kJ/mol,表明该体系的凝胶化作用对温度的敏感性增大。

The rheological behaves of polyether-ether ketone （PEKC）- bismaleimide （BMI） system during isothermal curing was studied by in-situ rheology. The time and temperature dependence were discussed in detail. The influence of PEKC contents on the viscosity of the PEKC - BMI blends was investigated. The results show that the gel point of BMI resin is of the frequency dependence, while tanδ is frequency independent. The viscosity increase of PEKC - BMI resin system is caused by PEKC dissolving in BMI and BMI curing with the increasing temperature. Comparison of 110 ℃ with 130 ℃ shows that, at higher temperature, the viscosity increase of the composite resin system is mainly caused by BMI resin curing. As the temperature increase, the gel time with increasing PEKC content shortens more rapidly, while the gel modulus increment becomes less. However, at lower temperature, the gel modulus increment becomes more with increasing PEKC content. With PEKC content of the resin system increasing, the apparent activation energy of gelation reaction increases from 4.9 kJ/mol to 65.9 kJ/mol. It is indicated that the temperature sensitivity of gelation behavior increases.