氨基化改性BN纳米片对环氧表面绝缘特性的影响

Effect of Amino Modified Boron Nitride Nanosheets on Surface Insulation Properties of Epoxy Resin

以尿素和六方氮化硼为原料通过球磨法制备了氨基化改性氮化硼纳米片(BNNS),并将改性前后的BNNS与环氧树脂混合制备BNNS/环氧复合材料,研究氨基化改性BNNS对环氧表面绝缘特性的影响。结果表明:通过球磨法成功将氨基接枝在氮化硼纳米片表面,改善了填料在环氧树脂复合材料中的分散性;相较于纯环氧材料,当改性BNNS的质量分数为0.5%时,BNNS/环氧复合材料的闪络电压提高了26.9%;此外,氨基化改性降低了材料表面的陷阱能级,加速了空间电荷消散速率;填充氨基化改性BNNS后复合材料的介电常数与介质损耗因数均有小幅提升,平衡空间电荷消散与极化弛豫两种效应对复合材料闪络电压的提升有积极作用。

Taking urea and hexagonal boron nitride as raw materials,we prepared an amino modified boron nitride nanosheets(BNNS)by ball milling method,and then prepared a BNNS/epoxy composite by mixing the BNNS before and after modification with epoxy resin.The effect of amino modified BNNS on the surface insulating properties of epoxy resin was studied.The results show that the amino group is grafted on the surface of BNNS successfully by ball milling method,which improves the dispersion of fillers in epoxy composites.When the mass fraction of the modified BNNS is 0.5%,the flashover voltage of the BNNS/epoxy composite increases by 26.9%compared with the pure epoxy resin.In addition,the amino modification reduces the trap energy level on material surface and accelerates the space charge dissipation rate.The dielectric constant and dielectric loss factor of the composites filled with amino modified BNNS increase slightly.The flashover voltage of the composites can be improved by balancing the effects of space charge dissipation and polarization relaxation.