Preparation And Antibacterial Properties' Study Of Polyurethane-nano Silver Materials

Polyurethane-nano silver materials has attracted much attention because of its excellent properties of polyurethane and nano silver,In order to prepare polyurethane-nanosilver,Thispaperfirstlyusesdifferentproportionsof polytetrahydrofuran,hydrogenated MDI,three hydroxymethyl propane,dimethylol propionic acid,1,6-hexanediol as raw materials for preparation of polyurethane film with different strength and hardness,So the optimum ratio of raw materials to prepare polyurethane film was found out.The polyurethane-nano silver film with antibacterial property was prepared by the method of heat treatment in situ reduction under this condition,Finally,the presence of silver particles in polyurethane-nano silver films was demonstrated by scanning electron microscopy(SEM)and X ray diffraction(XRD).Then,the hydrophobic surface modification of polyurethane-nano silver film was carried out to slow down the release rate of Ag~+of polyurethane film,so as to achieve the purpose of long-term antibacterial,Therefore,the two aryl diazonium methane with long chain alkane substituent was synthesized were prepared,and the molecular structure of the product was proved by NMR and FT-IR.Two methods of heat treatment and UV irradiation were used to modify the surface of polyurethane film and polyurethane-nano silver film.Through the contact angle measurement,the results show that the surface of the modified polyurethane film and polyurethane-nano silver film change from hydrophilicity to hydrophobicity,moreover,the heat treatment method has better contact angle and better hydrophobic property than that of the modified film by UV irradiation.On this basis,We also study the impact of dimethylol propionic acid content in polyurethane film on the film hydrophobic performance results show that adding dimethylol propionic acid,the film surface changed from hydrophobic to hydrophilic properties.Finally,the antibacterial properties of the polyurethane-nano silver films with silver nitrate content of 0%,1%,5%and 10%respectively,which were unmodified and modified by the two methods were studied,The results showed that the antibacterial properties of polyurethane-nano silver films were also increased with the increase of the content of silver nitrate,The conductivity test showed that the conductivity of polyurethane-nano silver thin film is smaller after modified,Which means the release rate of silver ion in aqueous solution is slow.