Preparation And Properties Of Lacquer Composite Anti-Corrosive Coatings

Metal is one of the basic material for various industries and heavy industries.When exposed to a certain environment,the metal materials were easily damaged resulting in various potential safety hazards and economic losses.It is estimated that the economic loss caused by corrosion accounts was up to 3-5%of the national GDP.Hence,the importance of metal protection awareness should be strengthened and regarded as a criticial step.Many reliable methods and strategies for preventing or reducing corrosion have been developed so far.Among them,the organic coatings,between metal and corrosive media,play a role in isolation and shielding and used widely with simple and effective method.However,facing environmental pollution as well as high corrosion costs,environmentally friendly coatings with low organic solvent volatilization(VOC)and low contamination,have received increasing attention.Naturally renewable raw lacquer,also known as national lacquer,can be cured into a film under natural conditions.Its lacquer film is widely used as a coating due to its durability,chemical resistance and the like.Base on the own excellent performance,the property should be improved such as corrosion resistance to oxygen,water and chloride ions impermeability of the medium.Therefore,when adding nanoparticles into the lacquer to form a hybrid organic-inorganic composite coating system,it can improve the anti-corrosion properties,and then expand the lacquer coating applications.To this end,different anti-corrosion inhibitors such as nano-preservatives were added into green material lacquer,to prepare anti-corrosion lacquer composite coatings.Mainly through the following aspects:1.The natural product sodium lignosulphonate,acrylamide and aconitic acid were synthesized lignin polymer LT,as water-based graphene dispersants.The LTG solutions(5 mg/mL)were uniformly dispersed graphene without any precipitation after 60 days.The prepared natural lacquer/graphene anti-corrosion coatings were composited according to different LTG proportion(3wt%,5wt%,10wt%).The structure and properties of all coatings were analysed by FTIR,UV-vis,TG,SEM,electrochemical and salt spray tests.The results shown that corrosion resistance of the composite coatings was significantly improved compared to lacquer coating,with the lowest Icorr value(4.153×10-10A/cm2)and higher PE(99.99%,90.11%)when added 5wt%of LTG dispersion.2.Lignin and aniline/p-fluoroaniline were synthesized as different anti-corrosion inhibitors(LS-PANI,LS-FANI,PF-37,PF-55,PF-73),then they respectively added into lacquer to prepared excellent composite anti-corrosion coatings.The prepared coatings were characterized with different analysis,such as FTIR,TG,XPS,SEM and electrochemical tests.And the results proved that PF inhibitors showed special anticorrosive effect when compared with different inhibitors.Importantly,the composite coating performed the lowest Icorr value and higher PE in 3.5wt%NaCl and 1.0M HCl solution when prepared with 10wt%PF-73 inhibitor.3.Chemically stable silane coupling agent(APTES--?-aminopropyl triethoxysilane,AATMS--N-aminoethyl-y-aminopropyltrimethoxysilane)was respectively reacted with urushiol to form anti-aging and anti-corrosion silicone polymer coating.Characterized by FTIR,TG,SEM,XPS,artificial accelerated xenon lamp aging,electrochemical and salt spray tests,the properties of coatings would be proved.The experimental results demonstrated that properties of silicone lacquer polymeric coating were significantly improved especially anti-aging and corrosion resistance.Among them,the film A revealed outstangding anti-aging properties of all coatings,performing aging resistance increased by 6 times compared with lacquer,and special corrosion resistance with the lowest Icorr value(2.476×10-10A/cm2)and the highest PE(99.99%,93.34%).