工艺因素对RTM成型聚酰亚胺复合材料性能的影响

Effect of process factors on the properties of polyimide composites prepared by RTM

采用低熔体粘度适用于液态成型的聚酰亚胺树脂研究了树脂传递模塑(RTM)工艺中树脂注射压力、注射流速、固化温度对碳纤维增强聚酰亚胺复合材料性能的影响,以确定最佳的成型工艺参数。结果表明,随着注射压力增大,复合材料的玻璃化转变温度下降,层间剪切强度提高,弯曲强度略有提升。随着注射流速增加,复合材料玻璃化转变温度不变,层间剪切强度和弯曲强度降低。随着固化温度升高,复合材料的玻璃化转变温度升高,但固化温度达到400℃时,层间剪切强度和弯曲强度明显降低。根据树脂工艺性,综合考虑复合材料内部质量、耐热性和力学性能,采用注射压力1.2 MPa,注射流速15 mL/min以及固化温度380℃的成型工艺较优。

The polyimide resin with low melt viscosity suitable for liquid molding was applied to study the effects of resin injection pressure,injection flow rate and curing temperature on the properties of carbon fiber reinforced composites prepared by resin transfer molding(RTM)process,in order to determine the optimal molding process parameters.The results showed that with the increase of injection pressure,the glass transition temperature of the composites was decreased,the interlaminar shear strength was increased,and the flexural strength was increased slightly.With the increase of injection flow rate,the glass transition temperature of the composites remained unchanged,and the interlaminar shear strength and flexural strength were decreased.With the increase of curing temperature,the glass transition temperature of the composites was increased,and the interlaminar shear strength and flexural strength were decreased significantly after cured at 400 C.According to the resin processability,considering the internal quality,heat resistance and mechanical properties of the composites,the molding process with injection pressure of 1.2 MPa,injection flow rate of 15 mL/min and curing temperature of 380℃was preferred.