| With the development of manufacturing industry,epoxy resin is increasingly used as the matrix of carbon fiber and other high-performance composites because of its high strength and low specific gravity after curing.In the composite system,carbon fiber and other reinforcements have very high corrosion resistance.In contrast,the corrosion resistance of epoxy resin as a matrix is not satisfactory.In a humid environment,water and other corrosion medium will slowly infiltrate into the epoxy resin,resulting in epoxy resin corrosion,resulting in structural damage,resulting in a significant decline in the performance of the whole composite,forming a great hidden danger.Therefore,it is of great significance to further improve the corrosion resistance of epoxy resin to prolong the service life of itself and its composites.At present,researchers often reduce the surface energy of epoxy resin and improve its hydrophobicity and barrier performance to corrosion medium by grafting fluoropolymer,silicone segment or directly doping graphene into epoxy resin.However,in this paper,starting with the modified epoxy resin curing agent,fluorine is introduced into the system while curing the resin to achieve the corrosion resistance of epoxy resin.In addition,the effect of modified graphene oxide on the corrosion resistance of epoxy resin was also studied.The design idea of this paper is relatively novel,which lays a solid research foundation for the wide application of epoxy resin and its composites in marine ships,marine engineering equipment,military industry and other fields.The specific research work of this paper is mainly divided into the following two parts:1)Diethylenetriamine fluoride was prepared by heptafluorobutyric acid and diethylenetriamine,and then the curing temperature of diethylenetriamine fluoride and E51 epoxy resin was determined by non-isothermal DSC method.Finally,pure epoxy resin castable(E51)and fluorinated epoxy resin castable(F-E51)were prepared with diethylenetriamine and diethylenetriamine fluoride respectively.After testing,the results show that: compared with E51 resin castable,the F-E51 with fluorine has better thermal stability;the hydrophobicity is obviously improved,the contact angle to water is increased from 69.5 °to 95.1 °.And the surface energy is reduced from 40.81mN/m to 29.27 mN/m;in the immersion experiment.After soaking for 24 hours,the water absorption of E51 is 0.34%,compared with E51,the water absorption of E51 is only 0.14%.The tensile strength and bending strength of the two kinds of resin castable were similar before soaking,and the E51 strength decreased by 9.51% and 7.76% respectively after soaking for 30 days,while the F-E51 only decreased by 2.04% and 1.86% respectively,indicating that the corrosion resistance was significantly improved.2)The modified graphene oxide((MGO),)was prepared by the reaction of ?-(2-epichloropropyl)propyltrimethoxysilane(KH560)with graphene oxide to increase the epoxy group on the surface of graphene oxide to improve its compatibility with epoxy resin.Then resin castable with a MGO content of 0,0.1%,0.3%,0.5%,0.7%,respectively,were prepared.The results show that compared with the pure E51 resin castable,the thermal stability of the castable is slightly enhanced,the hydrophobicity is effectively improved,the contact angle increases to 91.3 °and the surface energy decreases to 32.43 mN/m with the increase of MGO.And determined that the best proportion of adding MGO is 0.3%,under this ratio,the water absorption of the resin soaked for 24 hours is 0.18%,and after the immersion test,the tensile strength of the resin castable only decreased by 3.27%,indicating that its corrosion resistance has been effectively improved. |
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