HGM@GO聚氨酯复合材料的制备和导热性能研究

Preparation and thermal conductivity study of HGM@GO/PU composite

首先通过氧化石墨烯(GO)包覆对空心玻璃微珠(HGM)进行表面改性,再经过物理混合制备改性空心玻璃微珠/聚氨酯复合材料,使用X射线衍射仪、扫描电子显微镜、热重分析仪对经过氧化石墨烯包覆改性的空心玻璃微珠进行形貌和结构分析,对改性空心玻璃微珠/聚氨酯复合材料进行力学性能、导热性能、热膨胀性能等测试。结果表明:使用氧化石墨烯包覆空心玻璃微球对复合材料的硬度、拉伸强度、压缩强度和弯曲强度均有一定提升。在空心玻璃微球添加量高于5%后,复合材料的导热性能开始优于纯聚氨酯材料,表明空心玻璃微珠表面的石墨烯层使材料内部形成了高导热通道,整体提高了复合材料的导热系数,使复合材料密度降低的同时具备更加优良的导热性能。对复合材料的热稳定性进行测试分析发现,在添加了空心玻璃微珠填料之后,复合材料的热膨胀系数随温度增加的趋势得到了很好的抑制,在180℃下仍能保持较好的尺寸稳定性。

The surface of hollow glass microspheres(HGMs)was modified by graphene oxide(GO)coating,and then the modified hollow glass microspheres/polyurethane composite(HGM@GO/PU)was prepared by physical mixing.The morphology and structure of the modified hollow glass microspheres was analyzed by X-ray diffractometer,scanning electron microscope and thermogravimetric analyzer.The mechanical properties,thermal conductivity and thermal expansion properties of the HGM@GO/PU composite were tested.The result showed that the use of graphene-coated hollow glass microspheres enhanced the hardness,tensile strength,compressive strength and bending strength of the composites.When the addition amount of hollow glass microspheres was higher than 5%,the thermal conductivity of the composites tended to be better than that of the pure polyurethane materials,indicating that a high thermal conductivity channel had been formed inside the material caused by the graphene layers on the surface of hollow glass microspheres.This improved the overall thermal conductivity of the composites and made the composites have better thermal conductivity while the density was reduced.The thermal stability test indicated that the thermal expansion coefficient increasing of the composite was well inhibited when temperature increasing.Even at 180℃,the dimensional stability of the composite was still maintained well.