Surface Modification Of GO And Modify To Polymer

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.