摘要:
用KH-550对氧化石墨进行改性, 再对其进行还原, 获得功能化石墨烯(FG), 未经干燥的FG经超声处理后可以稳定分散在质量比9∶1的丙酮/水混合液中; 在高速搅拌和超声分散条件下, 将FG分散液分散到室温硫化(RTV)硅橡胶中, 固化后得到纳米FG(nano-FG)/RTV硅橡胶复合材料。采用FTIR、TEM、SEM、XRD和DSC分析了FG及复合材料的结构和形貌。结果表明: KH-550连接到石墨烯片层表面上, 使其片层起皱、折叠, 部分发生了剥离, 层间距增大到3.46 ; FG经过超声处理后剥离成透明至半透明的片层; nano-FG/RTV硅橡胶复合材料的断面结构为褶皱结构, 不同于纯硅橡胶, 也未出现微观相分离; 与硅橡胶相比, 复合材料的Tg、Tm和结晶度均有所提高。复合材料的力学性能测试结果表明, nano-FG对RTV硅橡胶具有明显的补强效果, 当nano-FG质量分数为0.5 %时, nano-FG/RTV硅橡胶复合材料的拉伸强度比纯RTV硅橡胶提高了一倍多, 达到了0.43 MPa; 断裂伸长率也提高了52%, 达到了265%。
Abstract:
Graphite oxide was modified by KH-550, the modified graphite oxide was reduced to form functionalized graphene (FG) dispersing consistently in the acetone/water (mass ratio is 9∶1) solution by ultrasonic treatment before drying. The FG dispersion was intensively mixed for a certain time by ultrasonic treatment to disperse the nano-FG in α, ω-dihydroxy polydimethylsiloxane matrix and obtained an uniform and stable nano-FG/room temperature vulcanized(RTV) silicone rubber composite after curing. FTIR, TEM, SEM, XRD, and DSC analysis show that KH-550 bonds to the surface of FG sheet to make its layers wrinkled, folding and partially exfoliated, and broaden its layer spacing to 3.46 . FG exfoliates into transparent or semi-transparent layers after ultrasonic treatment. The uniform and wrinkled cross-section morphology of nano-FG/RTV silicone rubber composite, which is different from that of pure silicone rubber, shows that there is no micro-phase separation between the two parts. Compared with the pure silicone rubber, the Tg, Tm and crystallinity of all the nano-FG/RTV silicone rubber composites are improved. Mechanical property tests show that nano-FG reinforces silicone rubber a lot. The tensile strength and the elongation at break of composite with 0.5 wt% nano-FG are 0.43 MPa and 265%, respectively. The tensile strength more than doubles and the elongation at break increases 52% compared with that of pure silicone rubber.
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