Preparation And Performance Of Functionalized Silica Modified Silicone Coatings

The adhesion of fouling organisms will bring a series of problems to the normal operation of submarine pipelines,offshore equipment platforms,ships,and other fixed and mobile facilities and equipment.When fouling organisms adhere to the bottom of the ship,it will increase the navigation resistance of the ship,resulting in an increase in fuel consumption and carbon emissions,resulting in the waste of non-renewable resources.The use of antifouling coatings is one of the effective ways to solve marine biofouling.As a typical representative of fouling release coatings,silicone coatings have low surface energy fouling release function due to their physical and chemical properties.It is a research hotspot of environmentally friendly antifouling coatings technology.However,the mechanical properties and adhesion properties of the silicone coatings are poor,and the silicone coatings can’t inhibit the adhesion of diatoms.In this paper,aiming at the shortcomings of silicone coatings,three functionalized silicas were prepared through graft modification of hydroxyl-terminated polybutadiene,surface-initiated polymerization modification,and polymerization of natural antifouling active molecules on the surface of silica.Three functionalized silicas were applied to reinforced silicone coatings.The functionalized silica was characterized by FT-IR,XPS,and other means.The effects of functionalized silicas addition on the mechanical properties,adhesion strength,and antifouling properties of silicone coatings were studied.The functionalized silica is prepared by grafting modified aminated silica with isocyanate group-terminated polybutadiene,which is added to the silicone coatings to prepare the polybutadiene functionalized silica to reinforce silicone coatings.The dynamic viscosity of silicone resin was detected,and it was found that the introduction of the polybutadiene hydrophobic segment made the nanoparticles well dispersed and the binding ability with the silicone resin improved.The mechanical properties test showed that the mechanical properties of the polybutadiene functionalized-silica reinforced silicone coatings were significantly enhanced.When 5% of the functionalized-silica was added,the enhancement effect was the best,and the tensile strength of the coating could reach 0.96 MPa,the elongation at break is148.30%,and the elastic modulus was 0.963 MPa.While the mechanical properties of the coating were enhanced,more hydrogen bond donors from urethane groups and urea groups are introduced to enhance the adhesion of the coating to the epoxy coating.The adhesion can reach0.743 MPa when 5% of the silica was added.Through the desorption experiments after static diatom attachment,it was found that the desorption rates of polybutadiene-functionalized silicamodified silicone coatings to Navicula and Phaeodactylum tricornutum were 61.23% and74.78%.Atom transfer radical polymerization was used to initiate the polymerization of glycidyl methacrylate and 1,2-polypropylene glycol acrylate on the surface of silica to prepare surfaceinitiated polymerization functional silica.It was added to the silicone resin to modify silicone coatings.After grafting glycidyl methacrylate,the introduction of epoxy groups can enhance the interface interaction between the silicone coatings and the epoxy primer,the adhesion is improved to 0.78 MPa when 5% functional silica was added.After continuing to graft 1,2-polypropylene glycol acrylate,the silica dispersibility was good and the bonding resin ability becomes stronger.So the reinforcement effect on the silicone coatings was better.The tensile strength of the coating is 0.82 MPa when 5% functional silica was added.The elongation at break was 133.22%,the modulus of elasticity was 1.02 MPa,and the adhesion was 1.00 MPa.The Chlorella and Phaeodactylum tricornutum release rates of coatings were 59.75% and72.88%.The atom transfer radical polymerization method was used to introduce the natural antifouling active molecule eugenol and the fluorine-containing hydrophobic monomer octafluoropentyl methacrylate into the silica surface to prepare the natural antifouling active molecule grafted silica.It was applied to modify the silicone coatings.Through the static adhesion experiment of diatoms,it was found that when the functional silica was 55 adding,the coating had a good inhibitory effect on Navicula and Phaeodactylum tricornutum,and the inhibition rates were 89.37% and 72.48%.After the fluoro-monomer continues to polymerize on the silica surface,the fluoropolymer chains will precipitate on the surface of the coating.When 5% functionalized silica was added,the water contact angle of the coating was 120°,and the inhibition rates of the coating on Navicula and Phaeodactylum tricornutum were 94.09%and 90.73%.