Prepare And Performance Of UV-curable Antibacterial Coatings Based On Multi-Quaternary Phosphonium Salt

Microbial infections are one of the main causes of harm to human health and life-threatening.With the improvement of antibioetic resistance of pathogenic microorganisms,the antibacterial activity of traditional antibacterial agents is gradually decreasing.Recently,the antibacterial polymers based on the "contact sterilization" method have attracted research interests.And the design and synthesis of antibacterial polymers with high antibacterial properties,high chemical stability and non-volatile are one of the key and difficult points in the field of developing new antibacterial material.As the reported antibacterial mechanism of organic antibacterial polymer,the polycationic antibacterial agent interacts with the negatively charged phosphate group of the cell membrane to destroy the permeability of the cell membrane,thereby causing cell lysis or death.Therefore,increasing the positive charge density of antibacterial agent is one of the effective ways to improve the antibacterial activities of materials.On the one hand,trisquaternary phosphonium salt(TQPS)was synthesiesd through by eight steps reaction,and diethylenetriamine was used as raw material,synthesied by amino group protection,Miachael addition,lithium aluminum hydride reduction.On the other hand,1,6-bis(diphenylphosphine)hexane was used as raw material and reacted with p-bromophenol to synthesize gemini quaternary phosphonium salt(GQPS).Thereafter,GQPS was subjected on a monohydroxy protection,and then reacted with tris-(2-chloroethyl)amine to successfully synthesize hexaquaternary phosphonium salt(HQPS)after four steps of reaction.The antibacterial agents were embedded in the polyurthane acrylate(PUA)by UV-curing technology,and serial of PUA-TQPS and PUA-HQPS antibacterial films were prepared.Finally,surface-modified teprapod zinc oxide(S-ZnO)by silane coupling agent were synthesized and embedded in PUA with HQPS to prepare PUA-HQPS/S-ZnO antibacterial film.The above synthesis was characterized by1H NMR,31P NMR,high resolution liquid chromatography,organic elemental analysis and infrared analysis.In addition,a series of antimicrobial coatings were characterized by the test of scanning electron microscopy,thermodynamic stability,embedding rate,water absorption,pencil hardness,antibacterial activity and LIVE/DEAD(?)BacLightTM bacterial viability assay.The results show that the antibacterial coating film exhibits high antibacterial properties when embedded with less antibacterial agent.In addition,the synergistic antibacterial effect of PUA-HQPS/S-ZnO composite film was studied,and results indicated strong antibacterial activity with antibacterial rate exceeding 99.99%against S.aureus and E.coli.In conclusion,this paper prepared PUA-TQPS,PUA-HQPS and PUA-HQPS/S-ZnO antibacterial coatings.By increasing the positive charge density of antibacterial agents,the antibacterial coatings exhibited excellent antibacterial properties.The results would provide a new methods and ideas for design and synthesis of antimicrobial polymers.