Synthesis And Properties Of Structural Antibacterial Acrylate Emulsion Based On PHMG

With the strengthen of people's environmental and healthy consciousness,antibacterial materials have attracted more and more attention.Polyhexamethylene guanidine(PHMG),which is a safe and efficient cationic antibacterial agent with a novel structure,also causes great concern.PHMG has broad-spectrum bactericidal and non-toxic harmless,and it doesn't produce drug resistance.In our study,a series of PHMGs with narrow molecular weight and controlled groups were synthesized by controlling the ratio of reaction raw materials,reaction time and reaction temperature with guanidine hydrochloride and hexamethylene diamine as the starting materials.The antibacterial modifier GPHMG with polymerizable double bond was synthesized by ring opening reaction between GMA's epoxy group and PHMG's amino group.The antibacterial monomer of GPHMG was introduced into the acrylic emulsion polymerization by semi-continuous seed emulsion polymerization to prepare antibacterial polyacrylate emulsion.The structure and properties of the antimicrobial monomers were tested by FTIR and MALDI-TOF-ES.And the antimicrobial properties of the synthesized PHMG were characterized by MIC test.The conversion of the reaction of GMA and PHMG was studied by UV spectrophotometry.The synthesized PHMGs were mainly composed of linear structure and a little branched structure.The optimum mole feed volume of GMA and PHMG was 2?2.5:1,the reaction time was 75 h,and the reaction conversion rate was about 75%.We studied the ratio of soft and hard monomer,emulsifier system,amount of initiator to determine the optimal synthesis conditions.The effects of the introduction of GPHMG on the properties of emulsion and polymer films were studied by means of particle size analysis,Zeta potential test,TQ DSC analysis,tensile test and antibacterial test.The optimal synthesis condition was that the amount of emulsifier occupied 4%of total monomer and the ratio was CTAC(cetyltrimethylammonium chloride):AEO-40(fatty alcohol polyoxyethylene ether)= 1:0.4.AIB A used as initiator with a dosage about 0.5%.The weigh ratio of soft and hard monomer was 0.9:1.Under these circumstances,the stability of the prepared emulsion was good,uniform and fine,the comprehensive performance was excellent.With the increase of the dosage of GPHMG from 0.5 wt%to 1wt%,the particle size of the emulsion was about 200nm,the distribution was narrow,the zeta potential was gradually increased,and the emulsion showed good stability.And the introduction of GPHMG didn't bring much influences on the thermodynamic properties of films.But the glass transition temperature of the films gradually decreased.When the content of GPHMG was increased,the tensile strength of films was gradually decreased,and the elongation at breaking increased gradually.The effective antimicrobial content of GPHMG was 0.9wt%in the antimicrobial films and the antibacterial rate of Staphylococcus aureus and Escherichia coli was 99.99%.When the weight content of GPHMG in the films was kept constant,the molecular weight of GPHMGs were between 500Da and 2000Da,the antibacterial property of the antibacterial films gradually increased with the increasing of the molecular weight of GPHMG and then the antibacterial property will gradually decreased.The antimicrobial stability of the structural antimicrobial film and the blended antibacterial film were compared.Structural antibacterial film had excellent antibacterial properties and stability,when compared to the blended one.The inhibition zone test showed that the structural antibacterial film had a non-leaching performance,which further explained that the structural antibacterial film had long-lasting and persistent antibacterial properties.