Synthesis Of Self-Crosslinking Cationic Silicone Acrylic Latex And Preparation Of Antibacterial And Stain-Resistant Coatings

The outbreak of the new type of coronavirus pneumonia has aroused widespread concern about the harmfulness of microorganisms.The development and use of long-lasting antibacterial and antivirus coatings applied to public places such as hospitals,schools,shopping malls and hotels can prevent the breeding and spread of microorganisms to a certain extent.Currently,most of the antibacterial coatings achieve the antibacterial properties of the coatings by adding small-molecule antibacterial agents.However,those coatings which prepared according to the above method have neither long-term antibacterial properties nor good stain resistance because small molecule antibacterial agent can overflow easily.Aiming to solve these problems which mentioned above,firstly,an acrylate-based antibacterial monomer was designed and synthesized in this paper.Then a self-crosslinking silicone-acrylic latex with antibacterial functional groups was prepared through free radical copolymerization.Thirdly,further research was focused on the comprehensive balance of antibacterial and stain resistance of the paint film.Finally,a water-based paint with good stain resistance and long-lasting antibacterial and poisonous effects was prepared through the formulation optimization.The main contents of the paper are as follows:1.Self-made antibacterial monomer dimethylaminoethyl methacrylate-butylammonium bromide(QAMC4),acrylate monomers,and polymerizable trialkoxy silicon monomers were used as raw materials,a self-crosslinking cationic silicone-acrylic latex with high solid content,small particle size,excellent mechanical and calcium ion stability was synthesized successfully according to the optimization of the polymerization formula The as synthesized latex was used as a filmforming substance to prepare a self-crosslinking paint with good antibacterial and stain-resistant sewage properties.It was found that the paint film is resistant to E.coli and Staphylococcus aureus by more than 99.99%before and after the ultraviolet light aging test,and the anti-mold grade is level 1.The overall stain resistance of the paint film interior wall reaches 45 points.2.In order to further improve the stain resistance of the paint film,the long-chain quaternary ammonium salt monomer dimethylaminoethyl methacrylate-dodecylammonium bromide(QAMC12)and allyltrimethylsilane(ATMS)monomer are introduced into the latex copolymerization process to prepare a highly stain resistant copolymer latex.Then,an excellent antibacterial and stain resistant sewage coating was prepared successfully by employing the synthetic latex as filmforming substance according to the in-depth study aboutand the relationship between the antibacterial performance,stain resistance of the coating,the structure of the polymer latex and the coating formulation.The stain resistance of the paint film is as high as 85 points,the pencil hardness is 2H,and the hiding power reaches the excellent product level.In addition,an experimental method to evaluate the antibacterial durability of the paint film was established,and the change of the antibacterial rate before and after the coating durability experiment were studied emphatically.It was found that after 20 times of wet-dry cycle durability test,10 times of temperature change cycle durability test and 30,000 times of scrub durability test,the antibacterial effects were>99.99%,>99.99%and 96.11%,respectively.3.Aming to improve the overall performance of the paint film,a new type of cross-linking system is introduced.Studies have shown that the introduction of new self-crosslinking monomers(with a dosage of 2%)improves the water-whitening resistance of the varnish film to level 5;the hardness of the white paint film is increased to 4H,and the ethanol wiping performance is increased by 5 times.In addition,the comprehensive performance of the self-made latex paint was comprehensively evaluated,and the test results met the requirements for use.Moreover,the antiviral performance was also characterized.The antiviral activity rate of the paint film against influenza A virus H3N2 and human coronavirus HCoV-229E with envelope structure reached 99.45%and 96.11%,respectively.