国产T700级碳纤维/BMI复合材料湿热性能

为研究国产碳纤维复合材料湿热性能,基于热压罐制备工艺,分别将国产T700级碳纤维和日本东丽T700S碳纤维与国产QY9611双马树脂进行匹配,从纤维表面物理/化学状态、吸湿曲线、吸湿后玻璃化转变温度、宏观力学性能等方面对2种复合材料开展湿热性能研究.结果表明:国产T700/BMI复合材料的饱和吸湿率为0.77%(35 d),T700S/BMI复合材料的饱和吸湿率为0.81%(19 d);71℃水浸168 h后,国产T700/BMI的玻璃化转变温度(T_g)下降10.3%(由252.1℃到226.2℃),T700S/BMI复合材料的玻璃化转变温度(T_g)下降8.7%(由256.6℃到234.3℃);150℃湿态环境下,国产T700/BMI复合材料90°拉伸强度与T700S/BMI基本相当,0°压缩强度较T700S/BMI高约17.9%,层间剪切强度较T700S/BMI高约9.3%,表明国产T700/BMI复合材料具有更优良的湿热力学性能.

Hygrothermal properties of domestic T700 carbon fiber/bismaleimide composites

In order to study the hygrothermal properties of domestic carbon fiber composites, both domestic T700 and Toray T700S carbon fibers were used as reinforcements to match with domestic QY9611 to prepare bismaleimide composites by autoclave moulding. Surface physical/chemical states of the carbon fibers, as well as moisture absorption characteristics, glass transition temperature after moisture absorption and hygrothermal mechanical properties of the two composites were studied. Experiment results show that the saturated moisture absorption rate of domestic T700/BMI and T700S/BMI is 0.77％(35 days), and 0.80％(19 days), respectively. After 168 h water immersion at 71℃, the glass transition temperature Tg of domestic T700/BMI and T700S/BMI decreases 10.3％ ( from 252.1℃ to 226.2℃) and 8.7％ ( from 256.6℃ to 234.3℃) , respectively. In 150℃hygrothermal temperature, domestic T700/BMI composite has an identical 90° tensile strength, 17.9％higher 0° compression strength and 9. 3％ higher interlaminar shear strength, compared with T700S/BMI, demonstrating that domestic T700S/BMI composite has a better hygrothermal and mechanical properties.