Preparation And Characterization Of Epoxy Nanocomposites With Excellent Anti-wear Performance

This paper mainly designs and prepares nickel phyllosilicate(NiPS)and its nano-hybrid materials,then introduces into epoxy resin(EP)as functional fillers to prepare EP nanocomposites.Firstly,the dimensional structure,thermal properties,and composition of the prepared nanofillers are characterized by various modern testing techniques,and then the influence of the content of the filler on the friction characteristics,mechanical properties,combustion behavior and curing process of the composite system is detailed.The main research results are as follows:(1)Using fumed silica(SiO₂)as the silicon source and hard template,and nickel nitrate(Ni(NO₃)₂·6H₂O)as the nickel source,NiPS with nano-flower-like structure was prepared by the deposition precipitation method(DP).It has good dispersibility and compatibility;when the content of NiPS is 5%,the glass transition temperature(T_g)is up to 169.2?.At this time,the tribological performance is the best,and the average coefficient of friction(COF)and wear rate(WR)reached 0.395 and 0.940×10^-5 mm³/N·m,respectively,which was 6.6%and 86.6%lower than pure EP(COF=0.423,WR=7.03×10^-5 mm³/N·m).Mechanical tests show that with the increase of NiPS content,the strength of NiPS/EP composites shows a trend of first increasing and then decreasing,while the elastic modulus continues to rise.When the addition amount is 5%,the tensile and compressive strengths reach the maximum of 92.9 and 280.05MPa respectively,while the tensile and compressive elastic modulus reach the maximum values of 1.57 and 1.77 GPa,respectively,when the content is 7%.Limiting oxygen index(LOI)and UL-94 vertical combustion test show that the introduction of a proper number of NiPS improves the flame retardancy of EP composites.Adding 3%can make the LOI reach27.5%,which is 16%higher than pure EP.After a single ignition It self-extinguishes after 80s,and there is no melt dripping.Differential scanning calorimeter(DSC)tests show that NiPS can promote the curing of the EP matrix and shift the curing peak temperature to a low temperature of about 10?.(2)On the basis of the flower-like NiPS prepared by the DP method,the NiPS supported nano-zinc sulfide(ZnS)hybrid(NiPS@ZnS)was prepared by the hydrothermal method.The microstructure and composition analysis showed that the ZnS loading did not change the flower-like shape of NiPS The lamellar structure is uniformly dispersed in the EP matrix,which significantly improves the T_g(162.4?)and mechanical properties of the composite material.Compared with the matrix material,when the addition amount is 5%,the tensile and compressive strengths reach the maximum of 86.1 and 259.02 MPa,increased by about 11%and 25%,respectively.while the elastic modulus showed a continuous increasing trend.Sliding dry friction test shows that the tribological performance of NiPS@ZnS/EP composite is the best when NiPS@ZnS content is 5%.At this time,COF and WR have reached 0.404and 0.494×10^-5 mm³/N·m,respectively.Compared with EP,it has decreased by about 12%and 93%.Compared with NiPS,although the addition of NiPS@ZnS did not further increase the LOI of the composite material,it shortened the self-extinguishing time after one ignition to 63 s,showing relatively good flame retardant performance.(3)In order to further improve the tribological properties of EP composites,CNT@NiPS with a core-shell structure was prepared by a combination of St(?)ber process and hydrothermal method.The study found that the increase in tensile strength of CNT@NiPS is significantly higher than that of NiPS and NiPS@ZnS at the same addition amount.When the addition amount is 5%,the tensile strength can reach 96.2 MPa,which is 24%higher than that of the matrix.Tribological tests show that CNT@NiPS can reduce the COF of the composite material.When the content is 3%,the COF(at steady status)of the composite material reaches the minimum value of 0.361,which is about 21%lower than that of the pure matrix,which is significantly higher than the anti-friction effect of NiPS and NiPS@ZnS on EP.The combustion test showed that CNT@NiPS made the self-extinguishing time of the composite material a minimum of 57 s.DSC test shows that a small number of CNT@NiPS can promote the curing of EP,while excessive addition will reduce the curing reaction rate of epoxy.Figure 48 Table 4 Reference 100...