Preparation And Properties Of Nano Silica/tung Oil Based Epoxy Resin Composites

Epoxy resin,as an important matrix for the development of composite materials,plays a vital role in advanced chemical manufacturing.However,with the promotion of sustainable development and the "dual carbon" policy,petroleum-based materials are gradually being replaced by bio-based materials.Vegetable oil is a low-cost biomass resource widely used to synthesize various bio-based materials.Among them,tung oil,as a non-edible vegetable oil,has active chemical properties and great potential for derivatives.By using tung oil to toughen and introduce nano-fillers for synergistic modification of resins,the mechanical properties of epoxy resin are improved,promoting the wide application of bio-based materials and achieving the substitution of petroleumbased materials.In this paper,two tung oil derivatives methyl eleostearate(ME)and epoxidized methyl eleostearate(EME)were prepared,and their effects on the mechanical properties,water resistance,and wear resistance of epoxy resin were investigated.Based on this,the influence of nano-SiO2 fillers on the wear resistance and mechanical properties of the composite material was studied.The main research results are as follows:(1)It can be inferred from the infrared spectra that ME and EME have undergone crosslinking reactions with the epoxy resin,successfully preparing ME-based and EME-based epoxy resin composite materials.EME is more effective than ME in improving the performance of epoxy resin.In terms of mechanical properties,the tensile strength and flexural modulus of the pure resin are 42.75 MPa and 2713.00 MPa,respectively.When the EME content is 10%,the tensile strength of the EME-based epoxy resin composite material reaches a maximum value of 62.75 MPa,which is 46.78%higher than that of the pure resin.The flexural modulus(4471.33 MPa)is 64.81%higher than that of the pure resin.The elongation at break of the pure resin film on both inner and outer surfaces is 5.30%and 9.21%,respectively.When the EME content is 10%,the flexibility of the film reaches the optimum value,and the elongation at break on the inner and outer surfaces is 21.86%and 37.50%,respectively,which is about three times higher than that of the pure resin.In addition,in terms of water resistance,the water contact angle of the 10%EME composite material(92.60°)is 25.13%higher than that of the pure resin(74.00°),and the water absorption of the EMEbased epoxy resin composite material is lower than that of the pure resin.(2)Overall,the wear resistance of tung oil-based epoxy resin composite materials is weakened.Under conditions of higher load and more friction cycles,the greater the mass loss and wear index of the composite material.Under the test conditions of a load of 500 g and 1000 cycles of friction,the mass loss and wear index of the pure resin are 2.2 mg and 0.0022,respectively.When the ME and EME content reaches 15%,the frictional mass loss of the composite material reaches the maximum values,which are 27.2 mg and 18.9 mg,respectively,and the wear index are 0.0272 and 0.0198.(3)The mechanical properties,wear resistance,and hydrophobicity of the nano SiO2/EME-based epoxy resin composite material are significantly improved compared to pure resin and EME-based epoxy resin materials.When the content of nano-SiO2 is 6%,the comprehensive performance reaches its optimum value.Under the test conditions of a load of 500 g and 1000 cycles of friction,the mass loss and wear index of the composite material are 4.5 mg and 0.0045,respectively.The wear index of the composite material is much lower than that of the EME-based epoxy resin,reduced by approximately 83.69%.Furthermore,the tensile strength and bending strength of the composite are 69.08 MPa and 130 MPa respectively,which are 10.00%and 20.37%higher than that of EME-based epoxy resin,and increasing by 61.70%and 52.94%,respectively,compared to the pure resin.In addition,as the content of nano-SiO2 increases,the water contact angle first rises and then falls.When the content of nano-SiO2 is 6%,the contact angle of the composite material can reach 104.76°,which is 41.57%and 12.28%higher than that of the pure resin and EME-based epoxy resin,respectively.The study shows that the addition of nano-SiO2 improves the wear resistance of the resin while also enhancing its mechanical and hydrophobic properties.