Synthesis And Properties Of Non-cyclic Halogen Amine Antibacterial Materials

Along with people living standard enhancement,people pay more and more attention to health quality.In daily life,the threat of microbial pollution to people's life safety often occurred,so the development of new antibacterial materials to protect the health and safety of people's lives is particularly important.At present,N-halamine antibacterial materials have attracted extensive interest of researchers due to their powerful antibacterial efficacy,regenerability of antibacterial functional groups,and broad-spectrum of antibacterial activity.However,not too much study on acyclic N-halamine materials has been done.In this thesis,a kind of macroporous cross-linked antimicrobial resin containing acyclic N-halamine polymer was synthesized and a kind of acyclic N-halamine grafted cotton fabric was prepared.The main research contents are as follows:(1)Study on synthesis and properties of macroporous cross-linked antimicrobial resin containing acyclic N-halamine polymerA kind of macroporous cross-linked resin containing acyclic N-halamine precursor polymer [P(AA-MBA-EPI)] was synthesized via a suspension co-polymerization of acrylamide(AA)and the cross-linking agents,N,N-methylenebisacrylamide(MBA)and epichlorohydrin(EPI).After a chlorination reaction in sodium hypochlorite solution,a macroporous cross-linked resin containing acyclic N-halamine polymer [P(AA-MBA-EPI-Cl)] was achieved.The as-synthesized P(AA-MBA-EPI-Cl was characterized by field emission scanning electron microscopy(FE-SEM),fourier transform infrared spectroscopy(FTIR),Brunauer-Emmet-Teller(BET)analysis,and X-ray photoelectron spectra(XPS).BET analysis and the test of oxidative chlorine content indicated that the as-synthesized P(AA-MBA-EPI-Cl had a very large surface area(124.9 m2 /g)and high percentage of Cl+(10.05%)which is favorable for the quick water disinfection.Antimicrobial tests showed that the as-prepared P(AA-MBA-EPI-Cl)resin was able to completely kill all of Staphylococcus aureus and Escherichiacoli(about 1×106 CFU/m L)within one min of contact,respectively.Also,the regenerability and storage stability of N-halamine functional groups in the as-prepared P(AA-MBA-EPI-Cl)resin were preliminarily evaluated.(2)Study on preparation and properties of acyclic N-halamine grafted cotton fabricMethylene-bis-acrylamide(MBA)was covalently bonded onto the cotton fabrics by an effective catalytic solid-state reaction in water.The as-prepared MBA grafted cotton fabric(cotton-MBA)was characterized by SEM image and FTIR spectra.After a facile chlorination in diluted Na OCl solution,the amide functional groups in cotton-MBA were converted to N-halamine ones and durable antibacterial cotton fabric containing stable noncyclic N-halamine groups(cotton-MBA-Cl)was achieved.Antimicrobial testing showed that the cotton-MBA-Cl could effectively inactivate 5.78×107 CFU/mL of S.aureus and 7.58×108 CFU/mL of E.coli O157:H7 completely within 1 min of contact time.Washing durability testing indicated that the oxidative chlorine percentage of the cotton-MBA-Cl was 0.06% after 50 washing cycles and could be recovered to 0.30% via a simple rechlorination.It means that the N-halamine antimicrobial groups and the covalent bonds between MBA and cotton are very resistant to washing.Storage stability testing showed that the oxidative chlorine percentage of the cotton-MBA-Cl decreased from 0.43% to 0.32% after 30 day's storage under room temperature,indicating that N-halamine functional groups are stable.Furthermore,it was found that the grafting and chlorination processes didn't have obvious bad effect on the tensile strength of cotton fabrics due to the mild grafting and chlorination conditions.