Preparation And Properties Graphene Oxide/Phenol Formaldehyde Resin In-situ Composition

Graphene oxide (GO) is an important graphene derivatives in the preparation of thegraphene, since the surface of GO contains a lot of oxygen functional groups that GO hasexcellent workability and solubility. GO can be well dispersed in aqueous systems and hasgood compatibility with polymer which has broad application prospects. In this paper, wewere synthesized graphite oxide by self-prepared. Well dispersion of GO by ultrasonicdispersion method and the morphologies and properties of GO sheets were characterized.GO/Phenol-formaldehyde (PF) composites were prepared by in-situ polymerization, andeffects of GO on the morphology of PF blends and the structure and properties of GO/PFin-situ composites were studied. The results are as follows:Graphite oxide was synthesized by a modified Hummers method and a good dispersibilityof GO were prepared by ultrasonic dispersion. The morphologies and properties of GO sheetswere characterized by FT-IR, TGA, WAXD and TEM methods. The results showed thatgraphite oxide has a lot of oxygen functional groups, such as hydroxyl, carboxyl and epoxygroups. GO by ultrasonic dispersion has an integral of chemical structure and the stability ofthe thermal performance. As the results showing by AFM and TEM, GO which synthesis bypresent experiment having a monolithic layer structure. The single layer thickness is about0.7-1.1nm and the transverse dimension is between300-1200nm.GO/PF in-situ composites were synthesized by in-situ polymerization. The morphologiesand thermal performance of GO/PF in-situ composites were characterized by DSC, TGA,WAXD and so. The results showed that GO by in-situ polymerization can be well dispersedin the PF matrix, the oxygen functional groups of GO has a strong interfacial interaction withPF and the addition of GO can improve the thermal performance. When GO loading contentsis1%, the initial decomposition temperature was increased by55.8oC.GO/PF composites were prepared through in-situ polymerization, blending andball-milling methods. The thermal properties, mechanical properties, dynamic mechanicalthermal analysis, creep and stress relaxation behavior of GO/PF composites with different GOadding methods were studied. The results showed that the properties of GO/PF compositeswere improved significantly by in-situ polymerization and ball-milling method. Whenaddition of GO by in-situ polymerization, the impact strength was increased by18.6%and theglass transition temperature (Tg) was raised up6.9oC. When addition of GO by ball-millingmethod, Tg was raised up7.9oC, as well as the creep and relaxation modulus were increasedby64.7%and58.6%, respectively.GO/PF in-situ composites with different contents of GO were prepared. The mechanicalproperties, dynamic mechanical thermal analysis and friction properties of GO/PF in-situcomposites with different contents of GO were studied. The results showed that when GOloading contents is0.5%, the storage modulus of composites was increased by78.3%andglass transition temperature raised up8.9oC. When GO loading contents is0.25%, the impactstrength was increased by18.6%, the wear rate of the composites was decreases by20%and15.6%at250oC and300oC, respectively. Creep and stress relaxation of GO/PF in-situcomposites has also been improved.Thermotropic liquid crystal polymer (TLCP) and PF firstly were prepared through meltextrusion methods, then adding GO and GO which modified by silane coupling agent KH550and KH560, respectively. The thermal properties, mechanical properties, dynamic mechanicalthermal analysis, creep and stress relaxation behavior of GO/TLCP/PF hybrid compositeswere studied. The results showed that the properties of GO/TLCP/PF hybrid composites werecertain improved. Especially when GO modified by silane coupling agent KH560, the impactstrength and the storage modulus were increased by25.6%and28.1%, respectively.