Study On The Preparation And Antibacterial Performace Of Diphenol Monomer And Their Polymer Materials

Microbial threats cause serious problems to human property and health.The wide spread of microbial threats can be treated with antimicrobial agents,which kills microbia or prevent microbia growth.Naturally antimicrobial agent is the futur e direction of development of antimicrobial agent.However,its disadvantages including poor resistance to heat,low antimicrobial effect and unreliabe raw resource,limit its industrialized production and wide application.To solve those problems,the antimicrobially active ingredients were extracted and identified,and then their analogues were obtained by using the chemical synthesis method.Compared with monomer,antimicrobial polymers demonstrate superior efficacy,reduced toxicity,minimized environmental problems,and higher stability.Herein we analyzed the structure of capsaicin,which is the antimicrobially active ingredient of chili.N,N?-[(4,5-dihydroxy-1,2-phenylene)bis(methylene)] bisacrylamide(OHABA)as the analogues of capsaicin was perpared by one-step process(Friedel-Craft alkylation reaction).Comparing with natural capsaicin,OHABA has higher antimicrobial performace.We polymerized OHABA into microspheres in a size-controlled manner via precipitation polymerization.The antimicrobial performaces of POHABA polymer spheres with different sizes were studied.Combining with vinyl organosilicon(VOSN),magnetic nanoparticle(Fe3O4)and polyethylene(PE)cling,different antimicrobial polymer materials were perpared.Their antimicrobial performances were studied.The monomer OHABA containing capsaicin derivative moiety was sysntheized by Fridel-Craft alkylation reaction.Catechol and N-methylol acrylamide(mole ratio of 1:3)as raw materials,in sulfuric acid/ethanol catalytic system,OHABA was perpared under 35 ? for 10 days with the yield as high as 73%.The structure of products was confirmed by Fourier Transform Infrared Spectroscopy(FT-IR)and Nuclear Magnetic Resonance Spectra(NMR).The reaction between catechins and Nmethylol acrylamide followed the mechanism of electrophilic substitution reaction.The potential barrier of disubstituted product was lower than monosubstituted product.And the active site of the carbon atom on monosubstituted product aromatic ring was more negative than that of the carbon atom on the catechins.As a consequence,disubstituted product was more likely to be generated,which consistented with the experimental results.Antimicrobial tests proved OHABA had broad-spectrum antimicrobial performances.The minimum inhibitory concentration(MIC)of OHABA again E.coli and B.subtilis were 6.4 mg/m L and 3.2 mg/m L,which were less than those of capsaicin.As an antimicrobial agent,OHABA had higher antimicrobial performance than natural capsaicin.Size-controlled poly-OHABA(POHABA)was prepared by precipitation polymerization,and its antibacterial performances were studied.POHABA spheres were obtained by mixing OHABA precursor and 2,2-azobisisobutyronitrile(AIBN)initiator in absolute ethanol at 70 ? for 10 h.By controlling the mass ratio of monomer and initiator AIBN from 1:0.05 to 1:8,POHABA with the size from 1.98 ± 0.13 ?m to 190 ± 50 nm were prepared.Antimicrobial tests also proved POHABA had broad-spectrum antimicrobial perfomance.The MIC of POHABA against E.coli and B.subtilis both were 0.4 mg/m L,which were lower than that of its monomer.The nano size polymer has better antimicrobial effect.Two kinds of antimicrobial core@shell material VOSN@POHABA and Fe3O4@POHABA were prepared by precipitation polymerization.VOSN@POHABA maintained broad-spectrum antimicrobial performance and stably antimicrobial ability after storaging for six months.By controlling the amount of OHABA,Fe3O4@POHABA core@shell materials with the shell thickness of 56 ± 12 nm and 10 ± 1 nm were prepared.The Fe3O4@POHABA nanostructure were easily recycled from aqueous suspensions with the simple help of a permanent magnet.Furthermore they retained 100% antimicrobial efficiency for E.coli and B.subtilis over eight cycles,indicating they have great potential as antimicrobial products in domestic water treatment,sewage disposal systems,and environmental protection field.POHABA was modified on the surface of PE cling by UV polymerization and precipitation polymerization,respectively.The UV-vis data showed that PE-PlasmaPOHABA-P cling prepared by precipitation polymerization had more POHABA on the surface of PE cling than that prepared by UV polymerzation.The antimicrobial test also showed PE-Plasma-POHABA-P cling has better antimicrobial effect.The MIC of PE-Plasma-POHABA-P cling against E.coli and B.subtilis was 97.7% and 91.4%,respectively.The quantity of POHABA on PE-Plasma-POHABA-P cling surface did not change before and after the antimicrobial experiment,indicating there would not have any food contamination for packaging of food.