Preparation And Performance Study Of Non-cyclic Haloamine Modified Polyvinyl Alcohol Film And Polyurethane Coating

In recent years,with the continuous improvement of people’s living standards,people begin to pay more attention to the external factors that harm their own health,and have more and more high demands for their own health.In the daily life,because of the widespread and extensive distribution of various bacteria and viruses in nature,they threaten people’s health,even endanger the harmonious stability of society and the sustainable development of the economy.Therefore,it is very important to study the new environmentally friendly and healthy antibacterial materials to safeguard people’s daily lives.At present,N-halamine antibacterial materials have attracted wide interest of researchers due to their powerful antibacterial efficacy,broad-spectrum antimicrobial activity,and reproducibility of antibacterial functional groups.In this thesis,on the basis of previous studies,a non-cyclic N-halamine-modified polyvinyl alcohol film and a non-cyclic N-halamine-modified polyurethane coating were successfully prepared and their performances were systematically studied.(1)Preparation and performance study of non-cyclic N-halamine-modified polyvinyl alcohol filmWith polyvinyl alcohol(PVA)and methylene-bis-acrylamide(MBA)as raw materials,a polymer containing N-halamine precursor functional groups(PVA-MBA)was obtained via grafting reaction between the active hydroxyl groups on PVA andα,β-unsaturated functional groups of MBA under the catalysis of sodium carbonate in an aqueous solution.Then,the non-cyclic N-halamine-modified polyvinyl alcohol(PVA-MBA-Cl)film was obtained via the chlorination of amide functional groups on PVA-MBA film.The preparation conditions of PVA-MBA-Cl film(molar ratio of grafted reactants,catalyst quality,grafting reaction temperature,grafting reaction time,and chlorination time)were optimized.The as-prepared PVA-MBA-Cl film was characterized by the field emission scanning electron microscopy(FE-SEM),infrared spectroscopy(FTIR),and X-ray energy spectrum(XPS).The performance test of PVA-MBA-Cl film showed that the tensile performance and the hydrophobicity were improved.The storage stability test indicated that the oxidative chlorine content of the as-prepared PVA-MBA-Cl film only decreased by only 11.87%after storage for 9weeks,indicating that the antimicrobial N-halamine functional groups in PVA-MBA-Cl film has excellent storage stability under room temperature.Antibacterial test showed that the as-prepared PVA-MBA-Cl film had very strong antimicrobial efficacies and could completely kill 1.28×10~6 CFU/mL of staphylococcus aureus and 1.89×10~6 CFU/mL of E.coli within 1 min.(2)Preparation and performance study of non-cyclic N-halamine-modified polyurethane coatingThe aqueous solution of a polymer(PVA-MBA)containing N-halamine precursor functional groups was mixed with water-borne polyurethane(PU)to obtain PVA-MBAmodifiedpolyurethane(PU&PVA-MBA)coatinglatex.The PU-PVA-MBA coating latex was evenly coated on the plate and dried to obtain PU-PVA-MBA coating.Then,a non-cyclic N-halamine-modified polyurethane(PU-PVA-MBA)coating was obtained by chlorination of amide functional groups in PU-PVA-MBAcoating.Theas-preparedPU&PVA-MBA-Clcoatingwas characterized by the field emission scanning electron microscopy(FE-SEM),infrared spectroscopy(FTIR),and X-ray energy spectrum(XPS).The performance test of the as-prepared PU&PVA-MBA-Cl coating showed that the hydrophobicity didn’t change a lot.The storage stability test indicated that the oxidative chlorine content of the as-prepared PU&PVA-MBA-Cl coating had only slight decrease after storage for 5weeks under room temperature,indicating that the antimicrobial N-halamine functional groups in PU&PVA-MBA-Cl coating has very good storage stability.Antibacterial test showed that the as-prepared PU&PVA-MBA-Cl coating had strong antimicrobial efficacies and PU&PVA-MBA-Cl1 and PU&PVA-MBA-Cl2could completely kill 1.28×10~6 CFU/mL of staphylococcus aureus and 1.89×10~6 CFU/mL of E.coli within 15 min and PU&PVA-MBA-Cl3 could completely kill 1.28×10~6CFU/mL of staphylococcus aureus and 1.89×10~6 CFU/mL of E.coli within 10 min.