Preparation And Antifouling Performance Of Eugenol Ester-based Acrylate Coating

The use of marine antifouling coatings is the most effective method to deal with the marine biofouling adhesion problems.However,most commercial antifouling coatings inhibit fouling adhesion to underwater surfaces by releasing toxic antifouling agents with harmful effects on marine ecology.To deal with the problems of marine ecological hazards of antifouling coatings as well as to reduce the dependence of the antifouling effect of coatings on antifouling agents,polymeric matrices with antifouling properties have become a research hotspot.In this paper,inspired by the antimicrobial substance eugenol,the eugenol ester-based acrylate polymer（EMFP）,eugenol ester-based acrylate polymer with quaternary ammonium component（EMQFP）,eugenol ester-based sulfobetaine acrylate polymer（EMFSP）and quaternary ammonium polymer modified graphene oxide/EMFP composite antifouling coating were designed and synthesized.And a surface nanoscale microstructure self-renewal antifouling strategy was proposed.In this paper,the chemical structure of the polymer was characterized by Fourier infrared spectroscopy（FT-IR）and nuclear magnetic resonance hydrogen spectroscopy（¹H NMR）,the release of eugenol from the coating in artificial seawater was studied by the UV spectroscopy and the X-ray photoelectron spectroscopy（XPS）.The surface wettability of the coating was characterized by contact angle test,the surface nanoscale microstructure of the coating was studied by scanning electron microscopy（SEM）and atomic force microscopy（AFM）.The antifouling ability of the coating was studied through bacterial adhesion experiments,diatom adhesion experiments and static real sea antifouling experiments in Qingdao sea in Shandong Province,and the antifouling mechanisms of different antifouling coatings were studied.The main contents are as follows:Eugenol methacrylate（EM）with antibacterial and antifouling properties was prepared by nucleophilic substitution reaction.Eugenol ester acrylate polymers（EMFP）were synthesized by free radical polymerization reaction using EM as the functional monomer for antibacterial and antifouling properties.It was shown that the surface hydrophilicity of the EMFP polymer coating increased after immersion in artificial seawater.The eugenol ester group of the polymer side chain hydrolyzes to release eugenol and the coating was able to self-renew in artificial seawater.The release rate of eugenol from the coating stabilized after 30 days.The release rate of the coating with the highest EM content of 25%by mass（EMFP-25）was the fastest at 0.14μg·cm^-2·day^-1.The inhibition efficiency of the coating against E.coli,S.aureus and Pseudoalteromonas marina was 90.4%,69.9%and 84.1%,respectively.Meanwhile,the inhibition ratios of the coating against Halamphora sp.and P.tricornutum were 59.5%and85.7%,respectively,which indicated that the coating was effective in inhibiting primary fouling adhesion.The mussels showed significant avoidance effect to the coating with high eugenol content.The EMFP was compounded into antifouling coating,and the antifouling effect of the coating was improved with the increase of EM content.Eugenol-based acrylate polymer（EMQFP）containing quaternary ammonium components was prepared based on the formulation of EMFP polymer（EMFP-10）with 10 wt.%EM and the addition of acryloyloxyethyl trimethyl ammonium chloride by free radical polymerization.The EMQFP had good film-forming properties and the rate of hydrolytic weight loss accelerated with increasing quaternary ammonium fraction content.The EMQFP showed better performance in inhibiting bacterial adhesion compared to the EMFP.The rate of eugenol release from the polymer（EMQFP-10）coating with the highest quaternary ammonium fraction content of 10 wt.%after 30 days of immersion in artificial seawater was 0.22μg·cm^-2·day^-1.The inhibition efficiency of the coating in E.coli,S.aureus and Pseudoalteromonas marina solutions were 87.7%,89.9%and 91.1%,respectively.The mussel selective adhesion experiments showed that mussels avoided coatings with high quaternary ammonium content.The EMQFP was compounded into antifouling coatings,and real sea antifouling experiments proved that the addition of quaternary ammonium components could improve the antifouling effect of the coatings.Based on the EMFP-10 formulation,the 2-（Dimethylamino）ethyl methacrylate（DMAEMA）was added to obtain eugenol ester-based acrylate polymer with tertiary amine structure in the side chain through free radical polymerization reaction,and then quaternized with 1,3-propanesulfonate lactone to obtain eugenol ester-based sulfobetaine acrylic zwitterionic polymer（EMFSP）.The coating exhibited good film-forming property and the hydrolytic weight loss rate accelerated with increasing SBMA content.The hydrophilicity of the EMFSP coatings after immersion in the artificial seawater increased with increasing SBMA content.The polymer with the highest SBMA content of 10%by mass（EMFSP-10）had a stable eugenol release rate of 0.19μg·cm^-2·day^-1 after 30 days of immersion.The inhibition efficiency of the coating was 97.8%,96.2%and 95.3%against E.coli,S.aureus and Pseudoalteromonas marina,respectively.Meanwhile,the inhibition ratios of the coating against P.tricornutum and Halamphora sp.were 91.3%and 88.4%,respectively.The mussels exhibited tropism to coatings with high SBMA content.The EMFSP was compounded into antifouling coatings and the effectiveness of the coatings was proved by the real sea antifouling experiments.GO with polymer brush structure（GO-PDMAEMA）was prepared by introducing vinyl on the surface of graphene oxide（GO）via KH570 and then reacted with DMAEMA via free radical polymerization,after which the quaternized polymer modified GO（GO-PQDMAEMA）was prepared by Menschutkin reaction with 1-bromobutane.The existence of both the DMAEMA structure in the cyclic conformation and the quaternized QDMAEMA structure on the GO-PQDMAEMA surface demonstrates the existence of both quaternary ammonium structure and zwitterion molecular structure on the GO surface.GO-PQDMAEMA was added to EMFP as a filler to obtain the GO-PQDMAEMA/EMFP composite coating.After immersion in artificial seawater,the nanoscale microstructured surface of the filler inside the coating could be exposed by the self-renewal of the coating surface.The composite coating exhibited good performance in inhibiting bacterial diatom adhesion.The presence of GO-PQDMAEMA weakened the interaction of mussel proteins with the substrate surface,making it necessary for mussels to further enhance the expression of foot adhesion protein genes to seek stable adhesion.The filler and resin were compounded to prepare the antifouling coatings,and the real sea antifouling experiments showed that the real sea antifouling effect of the coating improved with the increase of GO-PQDMAEMA.