纳米氮化硼/氧化石墨烯/聚氨酯基复合材料的制备及其导热和力学性能  

Preparation of Hexagonal Boron Nitride/Graphene Oxide/Polyurethane-based Nanocomposite and Its Thermal Conductivity and Mechanical Property

作　　者：乔友健 潘志东[1] 王燕民[1] QIAO Youjian;PAN Zhidong;WANG Yanmin(School of Materials Science and Engineering,South China University of Technology,Guangzhou 510640,China)

机构地区：[1]华南理工大学材料科学与工程学院,广州510640

出　　处：《硅酸盐学报》2020年第7期1062-1073,共12页Journal of The Chinese Ceramic Society

基　　金：广东扬帆创新创业研究团队计划(2015B090927002)资助;佛山市重大科技项目(2016AG101415)。

摘　　要：采用一种高能量密度的介质搅拌磨在添加高分子分散剂情形下将硅烷偶联剂改性后的六方氮化硼纳米颗粒和氧化石墨烯均匀预分散在高黏度聚氨酯预聚体中,而后加入扩链剂交联,制备了纳米氮化硼/氧化石墨烯聚氨酯基复合材料。分别探究了硅烷偶联剂改性氮化硼颗粒和氧化石墨烯的改性效果、分散剂对氧化石墨烯的分散效果以及单一和混合掺入氮化硼纳米颗粒和氧化石墨烯的含量对其聚氨酯基复合材料导热和力学性能的影响。另外,通过等效介质模拟计算和分析了氮化硼纳米颗粒或氧化石墨烯与聚氨酯基体界面的Kapitza热阻率。采用激光导热仪、耐磨试验机、Shore硬度计、扫描电子显微镜、红外光谱仪及红外成像仪对样品的改性分散效果、导热及力学性能进行表征。结果表明,通过改性后的纳米无机颗粒与聚氨酯基体相容耦合性好;当改性纳米氮化硼和氧化石墨烯的掺入量分别为10%和2%(质量分数)并有效分散在聚氨酯基体中时,其聚氨酯基复合材料的热导率为(0.671±0.033)W/(m·k),相对于未掺入纳米颗粒的聚氨酯材料(0.233 W·m–1·K–1),提高了188%。这主要归因于在有效分散的条件下掺入改性纳米氮化硼或氧化石墨烯可使其与聚氨酯基体界面的Kapitza热阻率降低。另外,经力学性能测试表明,改性纳米氮化硼/氧化石墨烯聚氨酯基复合材料的Shore硬度和磨损率分别为91和2.03%,相对于未掺入纳米无机颗粒的聚氨酯材料,分别提高了4.12%和降低了26.63%。A polyurethane-based nanocomposite with modified hexagonal boron nitride(h-BN)nanoparticle/graphene oxide(GO)was fabricated via effective dispersion of modified h-BN and GO into highly viscous polyurethane prepolymer in the presence of a polymer dispersant in a high energy-density stirred bead mill and subsequently crosslinking with a chain extender.The effects of h-BN and GO particles modified by a saline coupling agent,dispersion and h-BN and/or GO contents on the thermal transport capacity and mechanical properties were investigated,and the Kapitza thermal resistivity at the interface between h-BN nanoparticle or graphene oxide and polyurethane matrix was calculated based on the effect media approximation.The samples were characterized by thermal diffusivity measurement,wear rate analysis,Shore hardness measurement,scanning electron microscopy,infrared spectroscopy and infrared image.The results show that the nanoparticles modified by a saline coupling agent and dispersed with a polymer dispersant in the mill have a good compatibility with polyurethane matrix,thus enhancing the thermal conductivity of the nanocomposite,i.e.,(0.671±0.033)W/(m·K),which is increased by 188%,compared to neat polyurethane,i.e.,0.233 W/(m·K).This is possibly because the incorporation of modified h-BN nanoparticles or graphene oxide into polyurethane matrix can reduce the Kapitza thermal resistivity at their interface.Also,the Shore hardness of the polyurethane-based nanocomposite is 91,which is increased by 4.12%,and the wear rate is 2.03%,which is decreased by 26.63%,respectively,compared to those of neat polyurethane.

关 键 词：氧化石墨烯 氮化硼 聚氨酯 介质搅拌磨 力学性能 导热性能 Kapitza热阻率 

分 类 号：TQ317.3[化学工程—高聚物工业]