Preparation And Antifouling Performance Of Isoborneol-based Acrylate Coating

Traditional antifouling coatings use toxic antifouling agents to kill marine organisms attached to the surface of the hull,but toxic antifouling agents are easy to poison non-target organisms and have caused great harm to the marine environment.In this paper,inspired by the borneol material with antibacterial function,isoborneol-based acrylate fluorine coating（PBAF）,isoborneol-based acrylate zwitterionic coating（PBASA）and isoborneol-based acrylate boron self-polishing coating（PBAB）were designed and synthesized.Graphene/silver/isoborneol-based acrylate boron composite antifouling coating（PBAB/GAg）and carbon nitride/isoborneol-based acrylate boron composite antifouling coating（PBAB/C₃N₄）were further prepared based on PBAB polymer.The chemical structure of different polymers was characterized,the surface microstructure,wettability and antibacterial and antifouling properties of the coatings were studied,and the antifouling mechanisms of different coatings were discussed respectively.The specific research contents are as follows:Methyl methacrylate（MMA）and ethyl acrylate（EA）were used as structural monomers,hexafluorobutyl methacrylate（HFBMA）and isoborneol methacrylate（IBOMA）were used as antibacterial and antifouling functional monomers to synthesize Isoborneol acrylate fluoride polymer（PBAF）by free radical reaction,and then and then the PBAF polymer was cured into a coating.It was found that PBAF polymer could form stable film,and had good adhesion to substrate materials and maintain stable surface morphology in seawater.Isoborneol groups could significantly inhibit the adhesion of bacteria on the coating surface.At the same time,the existence of fluorine-containing groups reduced the surface energy of the coating and inhibitted the adhesion of diatoms.The antibacterial and antifouling experiments showed that the PBA₃F coating had the best antibacterial and anti-diatom adhesion properties,and the inhibition of bacterial attachment ratio of 24 h against Escherichia coli（E.coil）and Staphylococcus aureus（S.aureus）were 98.24%and 92.31%,respectively;only a few diatoms adhered on the surface after 14 days immersion in the solution of Halamphora sp.and Nitzschia closterium.Based on PBAF polymer,pigments,fillers and solvents were added to prepare antifouling coatings.After 11 months of static marine antifouling experiments in Dalian-sea area of Liaoning Province,no large fouling organisms were found on the PBAF coating surface.In order to further improve the antifouling performance of the coating,zwitterionic sulfobetaine（SBMA）was introduced into isoborneol acrylate polymer by quaternization reaction to prepare isoborneol-based acrylate zwitterion polymer（PBASA）,and then the antibacterial antifouling coating was prepared.It was found that the PBASA polymer maintained good stability in seawater,and the surface gradually became hydrophilic with the increase of immersion time.Isoborneol group and SBMA group jointly play an antibacterial role and resist bacterial attachment;at the same time,the hydrophilic property of SBMA groups could form a hydration layer on the surface of the coating to inhibit the adhesion of diatoms.The antibacterial and antifouling experiments showed that the PBASA-3 coating had the best antibacterial and anti-diatom adhesion properties,and the inhibition of bacterial attachment ratio of 24 h against E.coil and S.aureus were 92.58%and 83.06%,respectively.The 24 h anti-diatom adhesion rate was 92.18%,and only a small amount of diatom adhesion was observed on the surface after immersion in diatom solution for 14 days.Based on PBASA polymer,pigments,fillers and solvents were added to prepare antifouling coatings.After 6 months of static marine antifouling experiments,only silt and a few diatoms were found on the surface.In order to meet the long-term anti-fouling requirements of marine antifouling coatings,isoborneol-based acylate boron polymer（PBAB）was prepared by grafting pyridine triphenyl borane onto isoborneol-based acylate polymer with carboxyl side chain,and then antifouling coating was prepared.It was found that the surface of PBAB coating was gradually updated due to the hydrolysis of diphenylpyridine borane side chain in seawater,and the hydrophobic property of IBOMA component could significantly reduce the polishing rate of PBAB coating and prolong the application time of the coating.PBAB coating had excellent antibacterial and antifouling properties.The inhibition rates of PBAB-3 coating against E.coil and S.aureus were 95.18%and 81.15%,respectively.After 14 days of anti-diatom adhesion test,only a few diatoms attached on the PBAB-3 coating surface.Based on PBAB polymer,pigments,fillers and solvents were added to prepare antifouling coatings.After 11 months of static marine antifouling experiments,the actifouling performace of PBAB coating was excellent.Graphene nano-silver composite material（GAg）was prepared by loading silver nanoparticles on the surface of graphene,and PBAB/GAg composite coating was prepared by blending GAg with PBAB polymer.The effects of different GAg addition levels on the properties of composite coating were studied.The results showed that the PBAB/GAg-8 composite coating had the best inhibition of bacterial attachment ratio,and the inhibition rates of E.coil and S.aureus were 96.32%and 88.97%,respectively.The diatom adhesion resistance of PBAB/GAg-8 composite coating was better than that of pure PBAB coating.However,the immersion weight loss test results showed that the weight loss rate of PBAB/GAg composite coating was relatively fast,which will affect its application time in the marine environment.Based on PBAB/GAg,pigments,fillers and solvents were added to prepare antifouling coatings.After 7 months of static marine antifouling experiments,the antifouling effect was good,but it was found that PBAB/GAg-8 and PBAB/GAg-10 coatings showed large area of substrate due to excessive weight loss rate.PBAB/C₃N₄composite coating was prepared by blending graphite carbon nitride（g-C₃N₄）hollow nanopheres with PBAB polymer instead of GAg,the problem of excessive polishing rate of PBAB/GAg composite coating was solved,and its antibacterial and antifouling properties were studied.It was found that the addition of g-C₃N₄ hollow nanospheres should not exceed 8%,otherwise obvious agglomeration would occur.The·O₂^-and·OH produced by the compsite coating under light conditions also destroy the contact bacteria and diatom cells.The inhibition rates of the PBAB/C₃N₄-8 composite coating on E.coil and S.aureus were 92.59%and 86.17%,and the anti-diatom rate was 82.31%.Based on PBAB/C₃N₄,pigments,fillers and solvents were added to prepare antifouling coatings.After 6 months of static marine antifouling experiments,only a few diatoms were attached to the surface.