Study On Preparation And Corrosion Resistance Of Silane Anticorrosion Sealing Film For Iron Relics

Iron plays a crucial role in the development of social productive forces.It promoted the development of ancient productive forces and military strength.However,due to the non-uniform structure,more impurities,unstable properties,iron is very easy to be affected by the environment,and the existing and unearthed iron relics are corroded.Therefore,it is very necessary to protect iron cultural relics in order to extend their cultural life as long as possible.Sealing is one of the important methods to protect iron cultural relics.At present,the anticorrosive coatings with the alkyl siloxane as precursors have been widely valued,and have been used for anticorrosion of a variety of metal materials,and also used as sealing materials for iron cultural relics.In this paper,Silane coupling agent containing the group of corrosion resistance was prepared by heating and refluxing reaction of 3-glycidoxy propyl trimethoxy silane(KH560)and benzotriazole(BTA),called KH560/BTA silane anticorrosion sealing solution.Using carbon steel specimen to simulate iron relics.Silane anticorrosion sealing film was prepared on carbon steel by dipping method,and the film forming principle of Silane anticorrosion sealing solution on carbon steel surface was investigated by infrared spectrum analysis.Through single factor experiment and orthogonal test,the effects of reaction ratio n(KH560)/n(BTA),reaction temperature,reaction time and solution mass concentration on the preparation conditions of anticorrosion sealing solution were investigated.The results show that the optimum synthesis conditions of KH560/BTA anticorrosion sealing solution were as follows: n(KH560)/n(BTA)= 1:1.2,reaction temperature 130 ℃,reaction time 1 h,and solution mass concentration 30%.Under the best conditions of the synthetic process of anticorrosion sealing solution,the optimum process conditions for film formation were determined by examining the influence of factors such as dipping temperature,dipping time,curing temperature,and curing time on corrosion resistance.The corrosion resistance is compared with blank,KH560 hydrolysis and phosphating treatment sample by polarization curve,AC impedance,salt spray corrosion and NaCl immersion test.The results showed that the optimum conditions for film formation were as follows: dipping temperature 45 ℃,dipping time 60 s,curing temperature 120 ℃,and curing time 2 h.The results showed that compared to the corrosion resistance of the KH560/BTA anticorrosion sealing film and the single KH560 hydrolysis sealing film,the corrosion current density is greatly reduced,the impedance value is increased by dozens of times,and the corrosion resistance is greatly improved.Compared with the effect of phosphating treatment,the self corrosion current density has decreased by nearly one orders of magnitude,the film impedance value has increased by 3~10 times,the ability to resistance to NaCl solution soaking is enhanced.It can effectively prevent infiltration of corrosive medium and further improve the protection of iron matrix surface.In order to further improve the anticorrosion properties of the film layer,we added the amino silane coupling agent 3-amyl methyl two ethoxylsilane(APEDS)during the synthesis of KH560/BTA silane anticorrosion sealing solvent,and prepared a APEDS-KH560/BTA composite anticorrosion sealing solvent.And its synthetic process,preparation technology and corrosion resistance on iron substrate were also studied.The optimum preparation conditions of APEDS-KH560/BTA sealing film were determined by orthogonal experiments: n(KH560):n(APDES):n(BTA)=3:0.5:2,reaction temperature 100 ℃,reaction time 1.5 h,mass concentration 40%,dipping temperature 15 ℃,dipping time 120 s,curing temperature 80 ℃,curing time 2 h.Compared with the corrosion potential of APEDS-KH560/BTA and KH560/BTA anticorrosion sealing film layer,the corrosion potential is positively shifted,the corrosion current density is decreased,the corrosion resistance value is increased,the ability to resist sodium chloride and the corrosion resistance is enhanced.Finally,the rust specimen is selected as the protection object.Tannic acid,phosphoric acid,tannic acid phosphoric acid and phosphating liquid were used to convert the unstable rust layer to the stable rust layer and form the conversion coating.The converted sample was sealed with APEDS-KH560/BTA and KH560/BTA anticorrosion sealing solution respectively.The corrosion resistance of the conversion and conversion-sealing samples was tested by polarization curves,copper sulfate droplets,and neutral salt spray corrosion tests.The results show that the corrosion current density of the film transformed by the phosphating solution in the conversion sample is the smallest,and the corrosion degree is the lightest after the 8h salt spray corrosion test.Phosphating-APEDS-KH560/BTA anticorrosion sealing sample had the lowest corrosion current density,the longest salt spray resistance,little change after 24 h,and the best corrosion resistance.The protection effect of phosphating-KH560/BTA anticorrosion sealing sample is the next.This technology has a certain protective effect on iron Cultural relics,which not only improves the stability of silane treatment solution,but also improves the densification and corrosion resistance of the coating on the surface of the iron matrix,thus further improving the life of the film,which has a certain value of application.