The surface of carbon fiber (CF) was treated by hot air treatment and concentrated nitric acid treatment. Then nylon(PA) 12/CF composite powder was prepared by mechanical mixing. The mass ratio of carbonfiber to nylon 12 was 3:7. The composite powder material was injection molded, and the effects of heat treatment temperature and concentrated nitric acid treatment time on the mechanical properties and thermal properties of the composite powder material were investigated. The results show that the treatment effect is best when the condition of concentrated nitric acid treatment is 1 h,the tensile strength of injection molded strip is increased by 23％,theflexural modulus is increased by 133％,and VEKA softening point is increased by about 6.2℃. Scanning electron microscope results show that the treated carbonfibers are uniformly dispersed in PA12 matrix,and the interfacial compatibility is good.%利用热空气处理法和浓硝酸处理法分别对碳纤维(CF)进行表面处理,然后与尼龙(PA)12粉末按量比3:7通过机械混合法制备PA12/CF复合粉末材料.将复合粉末材料进行注塑成型,考察了热处理温度及浓硝酸处理时间对复合材料力学性能和热性能的影响.结果表明,浓硝酸处理时间为1 h处理效果最好,与未处理的CF复合材料相比,注塑样条拉伸强度提高23％,弯曲弹性模量提高133％,维卡软化点提高6.2℃;扫描电子显微镜分析表明,经过热处理后的CF在PA12基体中分散均匀,两者的界面相容性良好.
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