The Effect Of Carbon Fiber Cloth Modified By Shear Thickening Fluid On Mechanical Property Of Epoxide Resin Composite

The load can be transferred by the interface between the substrate of composite andreinforcing materials, which depends on the combination between the reinforcing materials andthe substrate. Accordingly, in order to improve the performance of the composite material, it isreasonable to control the interface. Based on the enhance body-carbon fiber and matrixmaterials-epoxy resin, we treated the carbon fiber cloth by surface modifier and acid, and thenprepared carbon fiber cloth reinforced/epoxy resin （CFS/EP） composites with the modifiedcarbon fiber, and valuated the interfacial properties.We utilized the stable polyethylene glycol （PEG） as solvent system to modify nano-SiO₂,prepared SiO₂/polyethylene glycol shear thickening fluid （STF）, and explored the optimumconditions for the modification of carbon fiber. The results indicated that: the obtained nano-SiO₂particles remains close and uniformly dispersed; C-O and C-H groups exist in the modifiedsurface of the SiO₂particles, and the Si-OH group peaks enhanced. SiO₂mass fraction, themolecular weight of the PEG and the ambient temperature all play significant impacts on theshear-thickening effect of the SiO₂/shear thickening liquid polyethylene glycol. When the massratio of the surface modifier SiO₂/PEG is3:10, and chose PEG400and PEG600blend as thedispersion medium, SiO₂/polyethylene glycol shear thickening fluid （STF） gained a better shearthickening effect.Secondly, we prepared the SiO₂/polyethylene glycol shear thickening fluid as surfacemodifier to modified the surface of the carbon fiber, and then studied the feasibility Process, theresults showed that: the trench in the surface of carbon fiber was filled up effectively after thetreatment of surface modification of SiO₂/polyethylene glycol STF, the trench in the surface ofcarbon fiber was filled up effectively, and the surfactant and wetting of carbon fiber cloth greatlyimproved due to the introduction of the Si-O-Si, Si-OH,-OH functional group, which provides agood foundation for the preparetion of high-performance carbon fiber cloth reinforced epoxycomposite.Finally, we prepared carbon fiber cloth reinforced epoxy composite and characterized its mechanical and interfacial properties, the results were as follows: the tensile strength of CFS/EPcomposite （H-CFS/EP, and H1H2-CFS/EP） pretreated by one-step and two-step oxidationdecreased compared with the untreated CFS/EP composite（A-CFS/EP）; the mechanical strengthof the carbon fiber CFS/EP composite treated by the SiO₂/polyethylene glycol shear thickeningfluid got improved remarkably, the tensile strength of A-CFS/EP, H-CFS/EP and H1H2-CFS/EPcomposites treated by the SiO₂/polyethylene glycol shear thickening fluid improved about26.08%,30.87%and37.56%respectively, and the interlaminar shear strength （ILSS） wereincreased by76.95%,35.44%and31.93%respectively; the interlaminar shear strength ofH-CFS/EP and H1H2-CFS/EP were increased by49.61%and58.54%respectively compared withthe A-CFS/EP for the improvement of specific surface. The method provides a new way of thingto improve the interfacial properties between carbon fiber and epoxy composite.