Study On Preparation And Properties Of Antibacterial Styrene-acrylic Emulsion And Its Application As Latex Paint

Styrene-acrylic latex paint has been widely used as interior wall due to its excellent properties.However,the surface of paint will be easily contaminated by bacteria during usage and cause potential harms to health of human.Therefore,developing antibacterial styrene-acrylic latex paint is not only meaningful in scientific research,but also valuable in real life application.According to the available researches,the antibacterial modification of styrene-acrylic latex paint was mainly based on adding non-reactive antibacterial agent,including inorganic antibacterial agent,organic antibacterial agent,and polymeric antibacterial agent.Unfortunately,the release of inorganic and organic antibacterial agent will result in the pollution of environment and short antibacterial durability.Though polymeric antibacterial agent will not release out of the substrate,the problems of compatibility with the substrate and the migration ability to the surface of the substrate still limit its application in styrene-acrylic latex paint.In view of the drawbacks of exisiting antibacterial styrene-acrylic latex paint,the antibacterial styrene-acrylic emulsions with durable antibacterial activity based on two novel reactive antibacterial agents were synthesized by immobilizing them into copolymer chains via emulsion polymerization.Then,styrene-acrylic latex paints with durable antibacterial activity were prepared using synthesizing emulsions.All the obtained results were listed as below:(1)A series of antibacterial styrene-acrylic emulsions(SA-Mn)were successfully synthesized by emulsion polymerization of previously synthesized antibacterial thiazole containing methacrylate in our lab(MEMT),styrene,butyl acrylate,and acrylic acid.The ATR-FTIR spectra confirmed that MEMT was successfully introduced into the copolymers.The addition of MEMT had no significant influence on the solid content,gel rate and monomer conversation rate of SA-Mn emulsion.With the increasing of MEMT content,the particle sizes,viscosity,the pencile hardness,and water contact angle of SA-Mn-F film were increased,while the water absorption and thermal resistance of SA-Mn-F film were decreased,and the antibacterial properties were strengthened.The antibacterial rate of SA-M20-F films against E.coil and S.aureus were both reached to 100%.Moreover,after being irradiated by UV light for 100h or immersed in water for 7 days,the SA-M15-F and SA-M20-F films still showed an antibacterial rate of more than 90%against E.coil and S.aureus,indicating excellent antibacterial properties and antibacterial durability.(2)Three kinds of methacrylate monomers containing bis-quaternary ammonium salt structures(MEQABr-x)weresynthesizedusing2-[[2-(dimethylamino)ethyl]methylamino]ethanol,bromoalkene(1-bromododecane,1-,bromotetradecane 1-bromohexadecane),and 2-isocyanatoethyl methacrylate as raw materials.The ~1H-NMR and FT-IR spectra confirmed that the chemical structures of MEQABr-x were the same as designed.All the MEQABr-x had excellent antibacterial properties,and MEQABr-14showed the best antibacterial properties against E.coil and S.aureus with the MIC of 4?g/m L,2?g/m L and the MBC of 16?g/m L,4?g/m L.A series of antibacterial styrene-acrylic emulsions(SAQx-n)were successfully synthesized by emulsion polymerization of MEQABr-x,styrene,butyl acrylate and acrylic acid.The ATR-FTIR spectra confirmed that MEQABr-x has been successfully introduced into the copolymers.The addition of MEQABr-x had no significant influence on the solid content,gel rate and monomer conversation rate.With the increasing of MEQABr-x content with the same alkyl chain length,the particle size of SAQx-n emulsion was increased at first and then decreased.For SAQx-n-F films obtained from SAQx-n emulsion,with the increasing of MEQABr-x content with the same alkyl chain length,the pencil hardness was decreased,the water contact angle was increased at first and then decreased,the water absorption was decreased at first and then increased,and the thermal resistance was decreased.With the increasing of alkyl chain length of MEQABr-x at the same content,the particle sizes decreased at first and then increased.For SAQx-n-F films obtained from SAQx-n emulsion,With the increasing of alkyl chain length of MEQABr-x at the same content,the water contact angle increased,the water absorption decreased,and thermal resistance increased.The addition of MEQABr-x improved the optical transmittance of films.(3)MEQABr-x could endow SAQx-n-F films with antibacterial activity,which was increased with the increasing of MEQABr-x content.The antibacterial rate of SAQx-9-F films against E.coil and S.aureus were both more than 98%.Moreover,after being irradiated by UV light for 100h or immersed in water for 7 days,the SAQx-9-F films still showed an antibacterial rate of more than 94%against E.coil and S.aureus,indicating excellent antibacterial properties and antibacterial durability.(4)The antibacterial styrene-acrylic latex paint PSA-M20 and PSAQ14-15 were further prepared by adding fillers and accessory ingredients into SA-M20 emulsion and SAQ14-15emulsion,respectively,and all of them exhibited excellent comprehensive basic properties.The films obtained from these two antibacterial styrene-acrylic latex paint showed antibacterial rate against E.coil of more than 95%and against S.aureus of 100%.After being irradiated by UV light for 100h or immersed in water for 7 days,the films still showed excellent antibacterial properties with the antibacterial rate of 95%,indicating its antibacterial durability.