Preparation And Properties Of Polyurethane Antibacterial Materials

Polyurethanes are a class of materials that are closely related to our lives and are increasingly used in various fields due to their excellent properties.It can be seen everywhere in furniture,insulation,sound insulation,transportation and even in the medical field.However,this material also has its fatal shortcomings,which are very susceptible to contamination by bacteria during use,which affects our production and even our lives.In recent years,more and more scientists have begun to develop a class of polyurethanes with their own antibacterial function.In order to modify the polyurethane,some small molecular groups with antibacterial properties are used by physical method.Although this method can be made into polyurethane antibacterial materials,it is easy to fall off.Especially in the medical field,once such problems occur,it will seriously endanger human health.As a result,more and more scientists are beginning to use chemical methods to synthesize polyurethane antibacterial materials which more stable.In this thesis,the BF₃·Et₂O/CF₃COOH cocatalytic system was used to synthesize PECH by ring-opening polymerization of epichlorohydrin?ECH?.The structure and molecular weight were determined by FTIR,¹H NMR,GPC.The experimental results show that PECH has been successfully synthesized and meets the molecular weight range we set?2000³000?.Then,N1-n-dodecyldiethylenetriamine?DDTA?with excellent antibacterial activity was prepared by the method reported in the literature,and then DDTA and tributylphosphine?TBUP?were grafted to the previously prepared PECH to make the PECH have antibacterial activity.The structure was determined by FTIR and ¹H-NMR,and the reaction conditions with the highest grafting rate were obtained by orthogonal test.In the grafting reaction between PECH and DDTA:using acetone as solvent,the reaction temperature is 80°C,the time is 12 h,the grafting rate can reach 26.9%;in the graft reaction of PECH with TBUP,acetone was used as a solvent,and the reaction temperature was 100°C,the time is 48 h,and the graft ratio is up to 18.6%when the ratio of controlled raw materials is 1:3.Next,the PECH grafted with the antibacterial group was synthesized into a polyurethane?PU?antibacterial material by a one-step method.The effects of catalyst and blowing agent on the reaction results were discussed,and the optimal raw material formula of PU antibacterial materials was obtained.At the same time,the physical properties of the PU antibacterial material were finally obtained by the tensile properties,scanning electron microscopy?SEM?and thermogravimetry?TG?.Finally,the most common harmful bacteria,Bacillus subtilis,Escherichia coli,Staphylococcus aureus were used to determine the antibacterial activity of the two products by inhibition zone and plate colony count.It shows that the two products have excellent antibacterial activity against all three bacteria,and the polyurethane grafted with N1-n-dodecyldiethylenetriamine has stronger antibacterial activity.The method adopted in this paper has great advantages compared with other methods:it can overcome the risks brought by physical methods without affecting the performance of polyurethane itself,and the antibacterial performance is more excellent.