Preparation And Properties Of Water-based Castor Oil Polyurethane Antibacterial Resin

Waterborne polyurethane(WPU)has the characteristics of environmental protection,green and safety,and can be a good substitute for solvent-based polyurethane.Polyols used in the preparation of WPU are mostly from fossil raw materials,which are non-renewable resources.WPU is easy to be interfered by bacteria in practical use,it is promising to develop antimicrobial WPU.At present,the main method to prepare antibacterial WPU is the introduction of antibacterial agents,the selection of antibacterial agents and the introduction of methods into the WPU system is very important,antibacterial agents have good antibacterial performance,but also need to be well integrated with WPU,can not destroy its original performance.Therefore,based on the castor oil-based WPU prepared in this experiment,castor oil-based antibacterial WPU was prepared by three different methods.The specific research contents are as follows.A series of cationic waterborne polyurethane emulsions were prepared using castor oil as the main raw material.With the content of cationic chain extender N-methyldiethanolamine(MDEA)changing from 6% to 10%,the mechanical properties of the film increased from 3.8MPa to 6.5MPa.Film antibacterial tests showed with MDEA content improve antibacterial performance improved,but the highest when the MDEA content was 10% film on escherichia coli and staphylococcus aureus antibacterial rate was 86% and 62%,far short of the demand of the actual use,so use in the process of WPU into salt sorbic acid(Sa)instead of acetic acid preparation of modified castor oil-based antibacterial cationic WPU with Sa.The Sa was successfully introduced into the WPU system by Fourier infrared.When the Sa content was 1.5%,the antibacterial rate of the film against Escherichia coli and Staphylococcus aureus reached 99.9%,and the antibacterial effect was excellent.We successfully prepared UV-curable WPU by introducing hydroxyethyl methacrylate(HEMA)in the process of WPU preparation on the basis of second part of this article.Under the same MDEA content,UV curing increased the crosslinking degree of the film.Compared with Chapter 2,the mechanical properties of the film increased by 5.9MPa and the water absorption of the film decreased by 3.0%.It is difficult for Sa to express its antibacterial properties under UV irradiation,so the guanidine salt antibacterial agent was introduced into WPU system through the reaction of amino and isocyanate in the emulsification process of WPU,and the UV-curable amino guanidine salt(AH)modified castor oil-based cationic antibacterial WPU was successfully prepared.After modification,the emulsion changed from translucent to milky white.The bacteriostatic zone test of the film showed that guanidine was successfully introduced into the WPU skeleton,and guanidine had no leachability.The antibacterial rate of Escherichia coli and Staphylococcus aureus was99.9% when AH content was 1.2%,and the antibacterial rate of the adhesive film was kept 99.9% after durability test.The double-bond functionalized G-?-PL was prepared by the reaction of ?-PL with glycidyl methacrylate(GMA),and then the UV-curable anion WPU was prepared.Finally,the antibacterial agent G-?-PL was ultrasonic dispersed into the anion WPU,and the UV-curable anion WPU film(PWPU)was prepared under the UV light condition.Compared with the original film,the water absorption of the PWPU film increased,the mechanical properties of the film increased by 2.4 MPa,and the water contact Angle of the film decreased from 66.0° to 58.9°.Agar diffusion test showed that G-?-PL had been successfully cross-linked into WPU system without spillover.The antibacterial test showed that the antibacterial rate of the prepared film against Escherichia coli and Staphylococcus aureus reached 99.9% when the amount of G-?-PL was 3%,and the antibacterial rate remained 99.9% after 14 times of repeated washing experiments.The antibacterial performance of the PWPU films was excellent and long-lasting.