石墨化竹炭的微观结构及其复合材料的制备与性能

Microstructure of graphitized bamboo charcoal and preparation and properties of its composite

采用SEM及XRD技术表征经2 800℃石墨化处理的竹炭的微观结构;以石墨化竹炭为导电骨料、酚醛树脂为粘结剂、炭黑为添加剂,采用模压成型法制备石墨化竹炭/酚醛树脂复合材料;考察石墨化竹炭的粒度、酚醛树脂用量、炭黑添加方式和用量、成型压力及固化温度等工艺因素对复合材料性能的影响。结果表明:增大竹炭粉粒的粒径、增加炭黑用量和提高固化温度有利于提高复合材料的导电性,但会不同程度地影响复合材料的力学性能、显气孔率和吸水率;随着酚醛树脂用量的增加,复合材料的抗弯强度提高,导电性、吸水率和显气孔率下降;提高成型压力可同时提高复合材料的性能;制备竹炭/酚醛树脂复合材料的最佳工艺条件为竹炭粒度≤75μm、树脂用量30%(质量分数)、炭黑用量5%(质量分数)、成型压力280 MPa、固化温度180℃。

The microstructure of bamboo charcoal graphitized at 2 800 ℃ was investigated by SEM and XRD.The bamboo charcoal/phenolic resin composite was prepared by compression molding technology,using bamboo charcoal graphitized at 2 800 ℃ as the conductive filler,phenolic resin as the binder and carbon black as the additive.The influences of the particle size of bamboo charcoal,resin content,adding way and content of carbon black,molding pressure and curing temperature on the properties of the composites were investigated.The results show that it is beneficial to improving the conductivity of the composites by increasing the particle size of bamboo charcoal,carbon black content and curing temperature,but the mechanical properties,porosity and absorption change more or less.With the increase of the content of phenolic resin,the flexural strength of the composite increases,in contrary,the conductivity,porosity and absorption decrease.Increasing the molding pressure can improve all properties of the composite simultaneously.The optimum particle size,resin content,carbon black content,molding pressure and curing temperature should be ≤75 μm,30%（mass fraction）,5%（mass fraction）,280 MPa and 180 ℃,respectively.