【作者】 王军；

【导师】 胡晓丹；

【作者基本信息】 南京航空航天大学 ， 工程硕士（专业学位）， 2018， 硕士

【摘要】 导热绝缘材料广泛用于电子封装胶领域,散热与绝缘是保证电子器件正常工作的关键,聚合物与导热绝缘填料的复合是制备电子封装胶的常用方法。传统型无机导热绝缘填料的添加量范围为30%-150wt%,高比重的添加量使得聚合物的其他性能受到影响,比如机械性能的下降。本课题采用石墨烯表面负载导热绝缘粒子（二氧化硅、氮化硼、氧化锌）复合材料作为填料,以加成型室温硫化硅橡胶为聚合物基体,在较低掺量的情况下制备研究了导热绝缘硅橡胶。首先以氧化还原法成功制备了石墨烯（RGO）以及用乙烯基三乙氧基硅烷对石墨烯接枝改性（FRGO）。RGO作为石墨烯复合填料的基底材料;利用FRGO的疏水亲乙醇的特性,在石墨烯基复合填料与硅油混合时,使用硅烷改性不仅可以增加填料的分散性,而且乙烯基的接入填料表面可以参与硅橡胶硫化时的硅氢加成反应,提高了填料与基体间的界面作用力。分别用溶胶凝胶法、溶剂热法、前驱体高温反应法制备了二氧化硅/石墨烯（SiO₂/RGO）、氧化锌/石墨烯（ZnO/RGO）、氮化硼/石墨烯（BN/RGO）复合材料。相关表征手段表明,SiO₂/RGO表层负载物为二氧化硅颗粒和少部分非晶态二氧化硅亚结构;ZnO/RGO表层负载物为六方纤锌矿结构的氧化锌;BN/RGO表层主要负载物为六方氮化硼。确定室温固化硅橡胶的配比后,将制备得到的三种石墨烯基复合填料使用硅烷改性后与硅橡胶复合,得到导热绝缘复合硅橡胶。1.0wt%掺量的SiO₂/RGO、ZnO/RGO、BN/RGO复合硅橡胶,热导率相对于纯硅橡胶分别提升了75.0%、80.5%、58.8%,体积电阻率分别为9.3×10¹³?·cm、1.1×10¹⁴?·cm、6.0×10¹¹?·cm,导热绝缘性能优异。且随着填料的增加,复合硅橡胶的热膨胀系数下降,耐热性能提升,介电常数与介电损耗保持在较低值,在电子封装材料领域,具有优秀的热学、电学性能。1.0wt%掺量时,复合硅橡胶的拉伸强度平均上升了125.6%、断裂伸长率平均提升了123.8%、硬度平均提升了24.4%,机械性能没有因为填料的掺入而下降且有一定程度的提高。相比需要高掺量传统导热绝缘填料的硅橡胶,本实验研究制得的硅橡胶获得导热绝缘性能的同时,硅橡胶的机械性能同时得到提升。更多还原

【Abstract】 Thermal insulation materials are widely used in electronic encapsulation adhesive,heat dissipation and insulation is the key to guarantee the normal work of the electronic devices,polymer with thermal insulation filler is the common preparation method of electronic packaging adhesive.Conventional inorganic thermal insulation filler has a range of 30%-150%wt,and the high proportion of added weight has affected other properties of the polymer,such as mechanical properties.This topic using graphene surface load thermal insulating particles（silica,boron nitride,zinc oxide）composite material as a filler,and room temperature vulcanized silicone rubber molding as polymer matrix,in the case of low content preparation of thermal insulation silicone rubber was studied.First,graphene（RGO）was successfully prepared by REDOX method and the modification of graphene grafted by vinyltriethoxysilane（FRGO）.RGO as the substrate material of graphene composite packing;Using FRGO hydrophobic characteristics and disperse better in ethanol,while graphene composite filler mixed with silicon oil,using silane modified can not only increase the filler dispersion,and vinyl access filler surface can participate in silicone rubber vulcanization silicon hydrogen addition reaction,improve the interfacial reaction between the fillers and matrix.With sol gel method,solvent hot method,precursor high temperature reaction of silica/graphene（SiO₂/RGO）,ZnO/graphene（ZnO/RGO）,boron nitride/graphene（BN/RGO）composite materials.The relevant characterization means that the surface loads of SiO₂/RGO are silica particles and a small number of amorphous silica structures.ZnO/RGO surface load is zinc oxide of hexagonal structure.The main load of BN/RGO surface is boron nitride.The three kinds of graphene-based compound fillers were prepared by using silane modified with silicone rubber,and the thermal insulation composite silicone rubber was obtained 1.0 wt%content of SiO₂/RGO,ZnO/RGO,BN/RGO composite silicone rubber,thermal conductivity,respectively,increase of 75.0%,80.5%,58.8%,volume resistivity were 9.3 x 10¹³?·cm,1.1 x 10¹⁴?·cm,6.0 x 10¹¹?·cm,excellent thermal insulation performance.And with the increase of filler,the thermal expansion coefficient of composite silicone rubber declined,heat-resisting performance improved,keep in relatively low dielectric constant and dielectric loss,in the field of electronic packaging material,has excellent thermal and electrical performance.Content of 1.0 wt%,the tensile strength of the composite silicone rubber average rose 125.6%,the elongation at break average rose 123.8%,shore hardness average rose 24.4%,mechanical properties without drops because of the incorporation of filler but a certain degree of improvement.Compared with the silicone rubber which needs high content of traditional thermal insulation filler,the mechanical properties of silicone rubber are improved simultaneously with the thermal insulation performance of the silicone rubber.更多还原