关键词: 聚酰胺6, 碳纤维复合材料, 氧化石墨烯, 机械性能, 导热系数
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Abstract: Carbon fibers were modified with graphene oxide (GO-KCF), polyamide 6/graphene oxide modified carbon fibers (PA6/GO-KCF), polyamide 6/pure carbon fibers (PA6/CF), and polyamide 6/graphite (PA6/graphite) were prepared by twin-screw extruder. The composition and thermal stability of modified carbon fibers, as well as the cross-sectional morphology, bending properties and thermal conductivity of the composite materials were analyzed. Infrared spectral analysis results confirmed the existence of —OH, —NH—, —CN—, O—Si—O and other structures in GO-KCF, indicating that graphene oxide was successfully grafted to the surface of carbon fibers. Thermo gravimetric analysis results show that GO-KCF has good thermal stability, and the mass loss rate is only about 3.5%. The cross-sectional SEM results of the composite material show that GO-KCF effectively improves the interfacial compatibility with the PA6 resin matrix and the dispersion in the matrix, the modified carbon fiber can form a three-dimensional network structure in the resin matrix, which can play the role of transmitting external force loads. When the addition amount of the modified materials is 11wt%, the bending strength of the PA6/GO-KCF composite material reaches 180 MPa, which is 38.5% and 24.1% higher than that of PA6/CF and PA6/graphite composites, respectively. The thermal conductivity test results show that the thermal conductivity of PA6/GO-KCF composites is better than that of PA6/graphite composites. With the same addition amount of 9wt%, the thermal conductivity of the PA6/GO-KCF composite reaches 2.42 W/m·K, which is 2.7 times and 3.9 times that of PA6/graphite and PA6/CF, respectively.

Key words: polyamide 6, carbon fiber composite, graphene oxide, mechanical properties, thermal conductivity