Synthesis And Properties Of Novel Biguanide Compounds

Nowadays,humans are still suffering from microorganisms,and drug resistance of microorganisms increases constantly.To reduce the threat of harmful microorganisms,it is very important to develop new antibacterial agents and antibacterial materials.The biguanide antibacterial agent has good antibacterial properties,can take effects without producing drug resistance and has other merit,and is capable to be a curing agent to cure the epoxy resin,so it has great research value.This paper designs and synthesizes novel biguanide antibacterial agents with excellent antibacterial properties.12 different biguanide derivatives are designed and synthesized by reacting 3 tolyl biguanides(o-tolyl biguanide,m-tolyl biguanide and p-tolyl biguanide)with 3 alkylamines(heptylamine,dodecylamine and hexadecylamine)and polyetheramine T403,respectively.The structures of the synthesized compounds were characterized by nuclear magnetic resonance hydrogen spectrum and fourier transform infrared spectrometer.The antibacterial properties of each biguanide derivative were expressed by the minimum inhibitory concentration,with Escherichia coli and Staphylococcus aureus were used as testing bacteria.It was found that each biguanide derivative has good antibacterial properties against both bacteria,and most of the biguanide derivatives have higher antibacterial effects against Staphylococcus aureus than against Escherichia coli.Among them,dodecyl o-tolyl biguanide has the lowest minimum inhibitory concentration which against Escherichia coli and Staphylococcus aureus is 3.8 ?g/mL and 2.5 ?g/mL,respectively.Meanwhile,the length of alkyl chain has a greater impact on the antibacterial properties.The non-isothermal curing kinetics of three biguanide derivatives and epoxy resin E51 system were researched by differential scanning calorimetry.The optimum curing reaction temperatures were calculated and the curing kinetic parameters and curing kinetic equation were concluded.The antibacterial properties of the cured product were tested by the effect of the cured product of the biguanide derivative/epoxy resin E51 system on the growth curve of Staphylococcus aureus.The results showed that the cured materials of each group inhibited the growth of bacteria.The cured product of dodecyl o-tolyl biguanide/epoxy resin E51 has the best antibacterial effect.When the absorbance of the drug-free control group is increased to 0.72,the absorbance of experimental group is 0.19.It is indicated that the synthesized biguanide derivatives still maintain certain antibacterial ability after curing with epoxy resin,and have the potential to be applied to the antibacterial resin material.