类金刚石网络结构石墨/环氧树脂导电复合材料的制备及性能研究

Research on the Preparation and Performance of Diamond-Like Network Structure Graphite/Epoxy Resin Conductive Composites

传统成型工艺制备的导电复合材料内部导电通路分布不可控,且难以实现复合材料的电学与力学性能的匹配。利用选择性激光烧结技术快速制备了类金刚石结构石墨骨架素坯,并经过二次固化、真空压力浸渍酚醛树脂溶液以及高温碳化等后处理工艺改善石墨骨架电学以及力学性能,并将环氧树脂与之“复合”,制备了石墨/环氧树脂复合导电材料。通过正交试验,研究了石墨骨架结构特征参数对导电复合材料的电导率和抗弯强度的影响。研究结果表明:键半径R为决定复合材料电导率的主要因素,但对于其抗弯强度为较次要因素;键长L对复合材料的电导率和抗弯强度皆为较主要因素;当键长为6 mm、键半径为1.4 mm、键角为120°时,可获得力学性能和导电性能相协同的新型导电复合材料。

The internal conductive pathway distribution of conductive composites prepared for traditional molding processes is uncontrollable,and it is difficult to match the electrical and mechanical properties of composites.In this paper,the selective laser sintering technology was used to rapidly prepare the diamond-like graphite skeleton blank,and the electrical and mechanical properties of the graphite skeleton were improved by secondary curing,vacuum pressure impregnation of phenolic resin solution and high temperature carbonization.The epoxy resin was"composited"with it,and graphite-epoxy composite conductive materials were prepared.Through orthogonal experiments,the effects of structural parameters of graphite skeleton on the conductivity and bending strength of conductive composites were studied.Results show that the bond radius R is the main factor determining the conductivity of the composite material,but it is a secondary factor for its bending strength.Bond length L is the main factor for the conductivity and bending strength of composite materials.When the bond length is 6 mm,the bond radius is 1.4 mm,and the bond angles is 120°,a new type of conductive composite material with mechanical properties and conductivity synergistic properties is obtained.