碳纳米管加入方式对碳纤维/环氧树脂复合材料层间性能的影响

针对碳纤维/环氧树脂预浸料,对比了直接在树脂中加入碳纳米管(CNTs)后制备预浸料以及将CNTs喷涂在预浸料表面2种CNTs加入方式对CNTs-碳纤维/环氧树脂复合材料层合板I型与II型层间断裂韧性及层间剪切强度的影响。通过对树脂黏度、固化反应以及玻璃化转变温度的考察,分析了CNTs含量对树脂性能的影响,考察了添加方法对CNTs长度与形态的影响。分析了2种CNTs加入方式对CNTs-碳纤维/环氧树脂层合板断裂韧性及层间剪切强度的改善效果与作用规律。结果表明:CNTs的加入使树脂的黏度提高,固化反应程度下降;2种分散方法对CNTs的长度与形态无明显影响;直接在树脂中加入CNTs对CNTs-碳纤维/环氧树脂复合材料I型与II型层间断裂韧性的提高效果低于在碳纤维/环氧树脂预浸料表面喷涂CNTs的方式,后者的CNTs利用率较高;由于CNTs团聚及对树脂固化反应的影响,CNTs含量过高会使得其对CNTs-碳纤维/环氧树脂层合板的增韧效果下降。

Effect of adding method of carbon nanotube on interlaminar property of carbon fiber/epoxy composites

The carbon fiber/epoxy prepregs modified by carbon nanotube (CNTs) were prepared by two methods, including directly dispersing CNTs in resin and spraying CNTs on surface of the prepregs. Mode I and mode II interlaminar fracture toughness as well as interlaminar shear strength of CNTs-carbon fiber/epoxy composite laminates fabricated by the two different prepregs were evaluated. The viscosity, curing reaction and glass transition temperature of resin were investigated to analyze the influences of CNTs content on resin properties. The length and morphology of CNTs in the two different methods were also compared. The modification effects and reaction law of adding CNTs methods on the interlaminar fracture toughness and interlaminar shear strength were discussed. The results show that the introduction of CNTs in resin causes an increase of resin viscosity and the reduction of curing reaction degree. These two methods have no significant effect on length and morphology of CNTs. For mode I, II interlaminar fracture toughness and interlaminar shear strength of CNTs-carbon fiber/epoxy composite, the improving degree from directly dispersing CNTs in resin is smaller than that from spraying CNTs on surface of carbon fiber/epoxy prepregs. The latter method has high utilization efficiency of CNTs. Moreover, high content of CNTs causes a decline of the toughening effect, resulting from CNTs aggregation and the effect of CNTs on resin curing reaction.