中文摘要：

利用石墨烯微片（GNPs）表面羟基与硅烷偶联剂反应,并通过原子转移自由基聚合（ATRP）方法在GNPs表面接枝了聚甲基丙烯酸甲酯（PMMA）。应用扫描电子显微镜、透射电子显微镜、红外光谱和X射线衍射方法分析了化学接枝前后GNPs的微观结构变化。将接枝PMMA的GNPs加入环氧树脂中,研究其对环氧树脂力学性能与尺寸稳定性的影响。研究结果表明,与原始GNPs相比,表面接枝PMMA的GNPs对环氧树脂力学性能的增强作用更明显。添加质量分数为0.5%的GNPs-PMMA可以使环氧树脂拉伸强度和模量分别提高17.4%和75%,弯曲强度和模量也分别增加了6%和12%,同时可以使环氧树脂在低于玻璃化转变温度的线性热膨胀系数（CTE）降低25%。

英文摘要：

After reaction of the silicane coupling agent with the hydroxyl on the surface of graphite nanoplatelets（GNPs）,polymethyl methacrylate（PMMA）was chemically grafted to the GNPs by using atom transfer radical polymerization（ATRP）.The microstructure change of raw GNPs and grafted GNPs was investigated by SEM,TEM,FTIR and XRD.The grafted GNPs were added into the epoxy resin,and the mechanical properties and dimensional stability of GNPs-PMMA/epoxy composites were studied.The PMMA grafted GNPs show better reinforcing effect on the mechanical properties of epoxy resin in contrast with raw GNPs.The tensile strength and modulus of epoxy resin increase by 17.4% and 75%respectively after being added 0.5wt% GNPs-PMMA.At the same time,the bending strength and modulus of epoxy resin exhibit enhancement of 6%and 12%,respectively.And the linear coefficient of thermal expansion（CTE）of epoxy resin declines by 25%below the glass transition temperature.