碳纳米管改性对环氧树脂复合材料热学和电学性能的影响

Influence of Modification of Carbon Nanotubes on Thermal and Electrical Properties of Epoxy Resin Composite

分别采用混酸(浓H_2SO_4和浓HNO_3)、浓HNO_3、浓NaOH及浓H_2SO_4/H_2O_2对碳纳米管(CNTs)在室温下进行表面处理,通过FTIR、SEM、DSC和TGA研究了各改性方法对CNTs/环氧树脂(EP)复合材料热性能和电性能的影响。结果表明,混酸处理使CNTs在EP中的分散性、EP的玻璃化温度和热分解温度都显著提高,其它3种方法也有这种作用,相比较而言,H_2SO_4/H_2O_2和HNO_3的改性作用稍差,而NaOH的最差。4种处理方法都使复合材料的导电性能、介电常数以及介电损耗显著下降,其中混酸处理使上述性能下降的程度最高,其次为H_2SO_4/H_2O_2处理,NaOH处理和HNO_3处理对电性能影响较小。

Carbon nanotubes（CNTs） are surface-modified using the mixed acid（concentrated H2SO4 and concentrated HNO3 ）, concentrated HNO3, concentrated NaOH and concentrated H2 SO4/H2 O2 at room temperature, respectively. The influence of these modifications on thermal and electrical properties of CNTs/epoxy resin（EP） composites is investigated by FFIR, SEM, DSC and TGA. The results show that the mixed acid treatment makes dispersion of CNTs in EP, the glass transition temperature and thermal decomposition temperature of EP to be significantly improved. The other three methods also have this effect. In contrast, the effect of H2 SO4/H2 O2 and HNO3 treatment is worse, and that of NaOH is the worst. The electric conductivity, dielectric constant and dielectric loss of the composites significantly decrease after CNTs are modified using each of the four treatments. The mixed acid treatment achieves the highest decrease of above properties, followed by H2 SO4/H2 O2 treatment. NaOH treatment and HNO3 treatment have a less influence on the electrical properties.