Preparation Of Quaternary Ammonium Salt Of Epoxy Resin And Its Application In Antibacterial Coatings

With the enhancement of people’s environmental awareness,environmental protection antibacterial coating has been paid more and more attention and widely used.Quaternary ammonium salt has good antibacterial properties and has been widely used in antibacterial coatings.The internal wall antibacterial coating prepared by epoxy resin quaternary ammonium salt has many advantages such as good antibacterial effect,low toxicity and high stability,which is a key point in research and development.In this paper,triethylamine hydrochloride was used to react with bisphenol A epoxy resin（E-44,E-51 and E-54）and phenolic epoxy resin（F-51）to prepare four kinds of quaternary ammonium salts.Then,a new type of environmental friendly interior wall antibacterial coating was prepared by mixing the interior wall coating with waterborne acrylate emulsion as the main component.The ring opening rate of different resins was studied by measuring the content of quaternary ammonium salt and epoxy value;The raw materials and products were characterized by FTIR;The thermal stability of quaternary ammonium salt was studied by DSC,and the antibacterial effect of quaternary ammonium salt of epoxy resin was studied by inhibition zone experiment.The results show that:In the ring opening experiment of epoxy resin and triethylamine hydrochloride,the ring opening reaction of E-54 is the easiest,and its ring opening efficiency can reach 98%.Under the same reaction conditions,the ring opening reaction of F-51 is the most difficult,and its ring opening efficiency is only 70.9%.Under the same conditions,the ring opening reactivity of four epoxy resins is E-54>E-51>E-44>F-51.The sample was treated quantitatively and characterized by FTIR.The peak of the original sample was sharp and wide at 912cm^-1（characteristic absorption peak of epoxy group）;the quaternary ammonium salt of the resin after reaction did not show a peak at this wavelength,the epoxy group was successfully opened;The thermal stability analysis showed that F-51 type phenolic epoxy resin quaternary ammonium salt had good thermal stability and temperature resistance of 183℃.In the inhibition zone experiment,the diameter of inhibition zone of triethylamine hydrochloride to Escherichia coli was 1.70cm at high concentration（3.6mol/L）;At low concentration（<0.72mol/L）,the diameter of inhibition zone was only 0.80 cm,which was equal to the diameter of Oxford cup（0.8cm）.Among the prepared quaternary ammonium salts of epoxy resin,the bactericidal performance of phenolic epoxy resin quaternary ammonium salt is better than that of bisphenol A epoxy resin quaternary ammonium salt.Under the same quaternary ammonium salt ion concentration,the bactericidal ability of the four quaternary ammonium salts of epoxy resin from large to small is F-51>E-54>E-51>E-44.When the quaternary ammonium salt ion concentration is 0.5mol/L,the corresponding inhibition zone diameters are 2.40cm,1.90cm,1.73cm,1.67cm.In this paper,the quaternary ammonium salt of epoxy resin was prepared by ring opening quaternary ammonium reaction of triethylamine hydrochloride and epoxy resin.The results showed that the bactericidal performance of phenolic epoxy resin quaternary ammonium salt film was better than that of bisphenol a resin quaternary ammonium salt film;Under the experimental conditions,the optimum formulation is that the quaternary ammonium salt of coating/resin（M∶M）is 1∶1.Under this condition,the inhibition zone diameter of phenolic epoxy quaternary ammonium salt coating film can reach 2.70cm.The experimental results provide data support for the small-scale test,pilot test and market stage of the coating,which is of great significance for the development of new interior wall antibacterial coating.