【作者】 张燕；

【导师】 王平华；

【作者基本信息】 合肥工业大学 ， 材料学， 2015， 硕士

【摘要】 石墨烯具有高强度、高透光率、高导电率以及高的比表面积等优异的性能,因而广泛地应用于晶体管、透明导电膜、储能技术、化学传感、功能复合材料等领域。然而,石墨烯易团聚、难分散、难溶解、难加工,严重地影响了其应用。为了解决此问题,需要对石墨烯进行表面修饰,以拓展其应用范围。本文运用原位自由基聚合法,以氧化石墨烯(Graphene oxide)为二维碳骨架,在GO表面接枝不同的聚合物,制备出GO复合纳米片,并将所得的产物运用于聚合物改性。主要研究内容与结果如下：1.采用原位自由基聚合法在GO表面接枝聚苯乙烯(PS),制备GO-g-PS复合纳米片,并以此对苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)进行改性。结果表明：SBS/GO-g-PS复合材料的力学性能、加工性能与热稳定性都优于纯的SBS和SBS/GO复合材料。动态力学分析(DMA)测试结果表明：SBS/GO-g-PS复合材料高温区的玻璃化转变温度(Tg)比纯SBS提高了4.2℃。2.采用原位自由基聚合法,在GO表面接枝聚丙烯酸丁酯(PBA),制备出GO-g-PBA复合纳米片,并以此对聚氯乙烯(PVC)进行改性。测试结果表明：GO-g-PBA复合纳米片均匀地分散在PVC基体中,PVC/GO-g-PBA复合材料的加工性能、热稳定性能与力学性能均优于PVC/GO复合材料以及纯PVC。当GO-g-PBA复合纳米片的质量分数为1%时,冲击强度与拉伸强度达到最大,分别为12.47 kJ/m2,42.89 MPa。PVC/GO-g-PBA复合材料的玻璃化转变温度较纯PVC提高了2.56℃。3.运用硅烷偶联剂(KH570)功能化GO,在GO表面引入更多的双键,再通过原位聚合法在GO表面接枝聚氨酯(PU),制得GO-g-PU复合纳米片,并以此对乙烯-醋酸乙烯共聚物(EVA)进行改性。结果表明：EVA/GO-g-PU复合纳米片的加工性能,热稳定性能,拉伸强度均优于EVA/GO复合材料以及纯EVA。当GO-g-PU复合纳米片的质量分数为4%时,拉伸强度达到最大,为8.21 MPa。DMA测试结果表明：EVA/GO-g-PU纳米复合材料的玻璃化转变温度较纯EVA提高了3.25℃。更多还原

【Abstract】 Graphene has excellent properties of high strength, high transmittance, high conductivity and high specific surface area, so it is widely used in various fields, such as transistor, transparent conductive film, energy storage, chemical sensors, functional composites. However, grapheme is easy to aggregate, difficult to disperse and process, which limits its application. In order to solve this problem, the surface of graphene should be modified. In this paper, graphene oxide (GO) is acted as a two-dimensional carbon skeleton, and different polymer chains are grafted onto the surface of GO. The resulting products are applied to modify some polymers. The main contents and results are summarized as follows:1. Polystyrene (PS) was grafted onto the surface of GO via in-situ radical polymerization, and the resulting GO-g-PS nanosheets were used to modify styrene-butadiene-styrene block copolymer (SBS). The results show that the mechanical properties, processing properties and thermal stability of SBS/GO-g-PS composites are superior to those of neat SBS and SBS/GO composites. The result of dynamic mechanical analysis (DMA) shows that glass transition temperature in high temperature region of SBS/GO-g-PS composite is 4.2℃ higher than that of neat SBS.2. Poly (butyl acrylate) (PBA) is grafted onto the surface of GO via in-situ radical polymerization, and the resulting GO-g-PBA nanosheets were used to modify poly (vinyl chloride) (PVC). The results show that GO-g-PBA composited nanosheets are uniformly dispersed in the PVC matrix. The mechanical properties, processing properties and thermal stability of PVC/GO-g-PBA composites are superior to those of neat PVC and PVC/GO composites. The impact strength and tensile strength of PVC/ GO-g-PBA composites reach the maximum value, while the mass content of GO-g-PBA composited nanosheets is 1%, amounting to 12.47 kJ/m2,42.89 MPa respectively. Glass transition temperature of PVC/GO-g-PBA composite is 2.56℃ higher than that of neat PVC.3. In order to introduce more double bonds to GO surface, silane coupling agent (KH570) was used to functionalize GO. Then, polyurethane (PU) chains were grafted onto the surface of GO. The resulting GO-g-PU composited nanosheets were used to modify ethylene vinyl acetate copolymer (EVA). The results show that the tensile strength, processing properties and thermal stability of EVA/GO-g-PU composites are superior to those of neat EVA and EVA/GO composites. The tensile strength reaches the maximum value, while the mass content of GO-g-PU composited nanosheets is 4%, amounting to 8.21 MPa. The result of DMA measurement shows that glass transition temperature of EVA/GO-g-PU composite is 3.25℃ higher than that of neat EVA.更多还原