Preparation Of High Antibacterial UV-Curable Coatings Based On Imidazolium And Quaternary Phosphonium Salts

The design and synthesis of antibacterial coatings with excellent antibacterial properties,high chemical stability and green environmental protection has always been the focus and difficulty in the field of coatings.The main research work is as follows:1.Preparation and performance of diimidazolium polyurethane acrylate coatings.By using imidazole,brominated alkanes(including 1-bromooctane,1-bromodecane,1-bromododecane)and dibromoneopentyl glycol as raw materials,a series of diimidazolium salts(DAIMCx,x represents the number of long alkyl carbon atoms)with dihydroxy functional groups were synthesized,and the structures were confirmed through 1H NMR and high-resolution mass spectrometry.After intercalating the DAIMCx in the backbone of polyurethane acrylate(PUA)and performing UV-light curing,the PUA-DAIMCx series coating film was synthesized,and the structure,physical-chemical properties and antibacterial properties were investigated.Results show that the antibacterial activity of the prepared coating film is proportional to the alkyl chain length of DAIMCx,and the PUA-DAIMC12-6wt%coating film has the best antibacterial performance,whose antibacterial rates against the gram-positive S.aureus and gram-negative E.coli reach more than 99.2%within 1 h.In addition,This coating film has good thermal stability,the pencil hardness is HB,and the water absorption rate is 2.25%.2.Preparation and performance of diquaternary phosphonium cationic polyurethane acrylate coatings.By the reactions between p-bromophenol and diphenylphosphine derivatives(including 1,6-bis(diphenylphosphine)hexane,1,5-bis(diphenylphosphine)pentane,1,4-bis(diphenylphosphine)butane alkane),a series of diquaternary phosphonium salts(DQPSx,x represents the number of species)with different cation spacing were synthesized.After the serial coating films are synthesized by DQPSx intercalating in the PUA main chain,their structure and performance were characterized.Among them,the diquaternary phosphonium salt with the closer cation distance has better antibacterial properties after being intercalated in the coating film.The prepared PUA-DQPS1-5wt%coating film achieves an antibacterial rate of more than 99.5%for the two bacteria,the pencil hardness is HB,the water absorption rate is 2.75%,and the thermal stability is good.3.Preparation and performance of diquaternary phosphonium cationic polyurethane acrylate coatings containing anti-adhesion ingredients.Heptafluorodecyl methacrylate in the form of active diluent was added to the PUA-DQPS1-5wt%coating film with good antibacterial properties.The water absorption rate of the prepared PUA-DQPS1-5wt%-F-8wt%film is 0.36%,and the film is in a hydrophobic state,which could improve the anti-bacterial adhesion of the coating surface.The antibacterial rate against the two kinds of bacteria reaches 99.9%.At the same time,the pencil hardness of the coating film is increased to 2H with a certain degree of flexibility.Therefore,the addition of anti-adhesion components could provide a new idea for the synthesis of UV-curable PUA coatings with high antibacterial properties,low surface adhesion and good thermal stability.