Study On The Syntheses And Properties Of Polymeric Resins Containing N-halamine/N-halamine Precursor And Quaternary Ammonium Salt Groups

The inadequate access to clean water caused by water pollution is one of themost challenges throughout the world. Solving this probelm calls out a tremendousamount of research to develop high-eiffciency new methods and materials for waterpuriifcation with lower cost. The water treated by traditional technologies andmaterials may recontaminated by harmful microorganisms due to the lack of lastingdisinfection in water. In recent years, developed N-halamine polymeric resin materialseffectively solved the microorganism recontamination problem as they can killmicroorganisms completely within a contact time of several seconds and release atrace of oxidative halogen into water for lasting disinfection. However, theN-halamine polymers reported have some limitations such as poor hydrophilicity andcomplex synthesis process. Recently, reverse osmosis membrance (RO) technologieshave been paid more and more attention as they can effectively removemicroorganisms, organics, and metal ions. However, the water purified by RO alsohas potential re-contamination of microorganisms and lacks some trace elementsessential for human body. In this paper, to solve the above-mentioned problems, wedesigned and synthesized three novel polymeric resins containingN-halamine/N-halamine precursor and quaternary ammonium salt groups. Theproperties of the as-synthesized polymeric resins were studied, and some satisfiedresults were received.Commercially available5,5-dimethylhydantoin (DMH) and macroporouscrosslinked chloromethylated polystyrene resin (CMPS) were used as startingmaterials to synthesize a novel macroporous cross-linked polymeric resin containing quaternarized N-halamine precursor gorups, poly(1-chloro-5,5-dimethylhydantoinyl-3-ethyl-p-ethenylphenylmethyl dimethylammonium chloride)(PSQH), which couldbe transferred to N-halamine polymeric resin Cl-PSQH upon exposure to dilutesodium hypochlorite solution. The as-synthesized polymeric resin was characterizedby the Fourier transform infrared spectra (FT-IR)，x-ray photoelectron spectroscopy(XPS), zeta-potential measurement, and Brunauer-Emmett-Teller (BET). Thehygroscopicity expeirment showed that the existence of quaternary ammonium saltfunctional groups in PSQH and Cl-PSQH improved their hygroscopic rates effectively.Antimicrobial tests showed that Cl-PSQH7could kill1.80><10CFU/mL ofStaphylococcus aureus and6.06><106CFU/mL of Escherichia coli0157:H7completely within1min of contact. When the water containing higher than3.Ox104CFU/mL of E. coli passed through the column filled with Cl-PSQH resincontinuously for14days, no viable bacteira were detected in post-column elffuentwater. Also, Cl-PSQH resin exhibited good regenerability and storage stability.We have developed an eco-friendly and economical technique to synthesize ahigh-eiffcacy macroporous cross-linked antimicrobial polymeric resin containing bothN-halamine and quaternary ammonium salt moieties，Cl-PSHTMA resin. Veryinteresting, all starting materials，5,5-dimethylhydantoin (DMH), trimethylamine(TMA)，macroporous crosslinked chloromethylated polystyrene (CMPS) resin, andNaOCl solution can be produced at industrial scales of thousands of tons; the onlyused solvent is "green" water. The attachment of quaternary ammonium salt moietiescan enhance the surface hydrophilicity of the resin, which makes DMH easily graftedonto the resin under the mild reaction temperature and short reaction time,avoiding the use of organic solvents. The as-synthesized polymeric resin wascharacterized by FT-IR, XPS, zeta-potential measurement, and BET. Antimicrobialtests showed that Cl-PSHTMA resin could kill1.80><107CFU/mL of Staphylococcusaureus and1.82><108CFU/mL of Escherichia coli0157:H7completely within1minof contact. When the water containing higher than3.Ox104CFU/mL of E.coli passedthrough the column filled with Cl-PSHTMA resin continuously for14days, no viablebacteria were detected in post-column elffuent water. The regenerability evaluation of Cl-PSHTMA resin showed that after10cycles of the quenching-rechloirnationtreatment, the Cl+%of Cl-PSHTMA resin was almost the same as the original value.The data for preliminary storage stability of Cl-PSHTMA resin indicated that theantimicrobial N-halamine functional groups are stable.A hydantoinyl derivative with tertiary amino group,(5，5-dimethylhydantoinyl-1-ylmethyl)-dimethylamine (DHDA), was synthesized by commercially availablel-hydroxymethyl-5,5-dimethylhydantoin and dimethylamine, and then gratfed ontomacroporous crosslinked chloromethylated polystyrene (CMPS) resin to form aquaternairzed hydantoinyl polystyrene resin, poly(5,5-dimethylhydantoinyl-1-methyl-p-ethenylphenylmethyl dimethylammonium chloride)(PDDC). PDDC resin could betransferred to polymeric functional resin immobili2zed with Zn+(PDDC-Z2n+) bytreating with sodium hydroxide solution and then zinc chloirde solution. Thedifunctional polymeric resin PDDC—-Z2n+-l3was prepared by treating PDDC-Z2n+wi"th I3solution. The as-synthesized polymeric resin was characterized by FT-IR andXPS2. The flowing water experiment showed that the concentrations of residual Zn+and I2in water were lower than0.31and0.93ppm, respectively, indicating thatPDDC-Z22n+-l3~could supply trace Zn+into water and prevent microorganismsre-contamination. Antimicrobial tests showed that PDDC-Z2n+-l3_could kill1.56><106CFU/mL of Staphylococcus aureus and8.60><106CFU/mL of Escherichia coli0157:H7completely within10min of contact. When the water containing higher than2.5x104CFU/mL of E. coli passed through the column iflled with PDDC-Z2n+-l3_continuously for12days, no viable bacteria were detected in post-column effluentwater. The as-prepared PDDC~-Z2n+-l3is expected to have potential applications inthe prevention of microorganism re-contamination as well as the supply of traceelements for the water treated by reverse osmosis membrance.