石墨烯纳米薄片-SiO2/天然橡胶复合材料的导电导热性能

Electrical and thermal properties of nano graphene sheets-SiO2/natural rubber composites

  • 摘要: 采用物理机械剥离法对可膨胀石墨进行剥离,得到厚为10 nm、横向尺寸为10~20 μm的石墨烯纳米薄片(GE),进一步制备GE质量分数为20wt%的GE/天然橡胶(NR)浓缩母粒;采用硅烷偶联剂KH580对SiO2进行改性,得到疏水性SiO2;采用机械共混的方法制备了GE质量分数分别为0、0.2wt%、0.5wt%、1.0wt%、2.0wt%的GE-SiO2/NR复合材料。对GE-SiO2/NR复合材料进行导电导热性能的测试,发现随着GE含量的增加,其导热导电性能逐渐提升,当GE含量为2.0wt%时,复合材料的面内导热率提高了38.1%,面间导热率提高了36.21%,导电率提高了36.07%。GE含量越高,GE-SiO2/NR复合材料的100%和300%定伸应力越大,拉伸强度、撕裂强度、断裂伸长率变化不明显。随着GE含量的增加,GE-SiO2/NR复合材料填料的网络效应减弱,Payane效应减弱,玻璃化温度逐渐升高。通过SEM分析发现,改性后的SiO2在NR基体中分散良好,无团聚现象,在GE含量为2.0wt%时,GE-SiO2/NR复合材料中能明显观察到GE的片层结构。

     

    Abstract: The expanded graphene was stripped by physical and mechanical stripping method, and the nano graphene sheets (GE) with thickness of 10 nm and horizontal size of 10-20 μm were obtained, and the GE/natural rubber (NR) concentrated masterbatch with mass fraction of 20wt% was further prepared. The hydrophobic SiO2 was obtained by modifying the precipitated SiO2 with the silane coupling agent KH580. The GE-SiO2/NR composites which contain 0, 0.2wt%, 0.5wt%, 1.0wt% and 2.0wt% GE were prepared by mechanical blending. By testing the conductive and thermal conductivity of the GE-SiO2/NR composites, it is found that its thermal and electrical conductivity gradually improve with the increase of GE content. When the GE content is 2.0wt%, the thermal conductivity in pane increases by 38.1%, the thermal conductivity through pane increases by 36.21% and the electrical conductivity increases by 36.07%. The higher the GE content, the greater the 100% and 300% tensile stress of the GE-SiO2/NR composites, but the change of tensile strength, tearing strength and breaking elongation are not obvious. With the increase of GE content, the network effect of filler and Payane effect are weakened, and the glass temperature gradually increases. According to the SEM analysis, the modified SiO2 is well dispersed in the NR matrix without agglomeration. When the GE content is 2.0wt%, the lamellar structure of GE is obviously observed.

     

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