| Epoxy resin(EP)has poor friction and wear properties due to its high degree of cross-linking.The addition of nano cellulose(NC)can improve the shortcomings of EP,such as brittleness and poor friction and wear performance,enhance the friction and wear performance of composite water-based coatings,and expand the application range of water-based coatings.In this thesis,polyethylene glycol(PEG)is used to graft-modify EP(EP-20)to synthesize type II EP water-based emulsion,add NC modified by silane coupling agent and graft EP to prepare NC composite type II EP water-based emulsion Coatings,the friction and wear test on them,to study the friction and wear properties of NC composite type II EP water-based paint.conclusion as below:(1)The best preparation process of water-based EP coating is: reaction temperature100℃,reaction time 5 h,triphenylphosphine(TPP)as catalyst,EP-20: PEG=1:1,EP-20:water-based epoxy curing Agent=2:1;Infrared spectroscopy(FT-IR)analysis showed that PEG and EP-20 had a chemical grafting reaction,introducing hydrophilic groups;scanning electron microscope(SEM)observed that the modified water-based EP coating was smooth and flat;transmission The electron microscope(TEM)observed that the particles of the water-based EP emulsion are evenly distributed,with good dispersibility and stability.(2)The best preparation process of NC composite II type EP water-based paint is:the addition amount of NC is 0.8% of EP-20,the amount of silane coupling agent KH560 is 0.9% of the NC suspension;SEM observes the distribution of NC in the coating Uniformity without agglomeration;TEM observed that NC is in the form of filaments,and the molecules are tightly intertwined to form a network structure,and the silane coupling agent is evenly dispersed on the surface of the NC;FT-IR analysis shows that NC and silane coupling agent KH560 Successfully grafted.(3)The best technical parameters of the friction and wear performance of the composite water-based coating are: the amount of silane coupling agent KH560 is 0.9%,and the amount of NC is 0.8%;compared with the water-based EP coating without NC:both friction and wear properties and tensile properties The tensile stress reached 4.2MPa,and the friction coefficient reached 0.133,which was reduced by 67.72%.The scratch friction and wear test and ultra-depth of field scratch morphology showed that the friction curve was relatively smooth,the fluctuation was small,and the friction surface was smoother;Observe the friction surface of the composite water-based coating by SEM,and analyze its friction and wear mechanism to be mainly fatigue wear,abrasive wear and adhesive wear;FT-IR analysis shows that NC has been grafted into EP,and the thermogravimetric(TG)curve shows that the composite water-based The thermal stability of the coating has been improved. |
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