Preparation Of Three-dimensional TPU/CA Porous Composite Foam And Its Application In Oil/Water Separation

In recent years,with the rapid development of petrochemical industry,oil pollution has become more and more serious,which poses a great threat to the ecological environment and human health.Compared with the traditional two-dimensional separation materials,three-dimensional porous foam material has the advantages of large specific surface area,high porosity,and good internal connectivity,which makes the oil more easily absorbed,storage,transportation,so it is used as in-situ oil-water separation material for fast,continuous and large capacity has caused more and more attention.In this paper,three-dimensional polyurethane/cellulose acetate(TPU/CA)porous composite foam was prepared by vacuum solution casting/particle leaching technology,and TPU/d-CA composite foam was obtained by deacetylation.The influences of molding process parameters and modification treatment method on the morphology,wetting performance,oil-water separation performance,self-cleaning performance and photocatalytic performance of the composite porous foam are mainly studied.The main work includes:1.Three-dimensional TPU/CA porous composite foam was prepared by vacuum solution casting/particle leaching technology,and characterized by scanning electron microscope(SEM),ethanol immersion method,adsorption method and contact angle measurement instrument.The effects of casting solution concentration and pore-causing agent salt(Na Cl)particle size on the morphology,porosity,oil absorption and surface wettability of three-dimensional porous composite foam were investigated.The results showed that the porosity and hydrophilicity of TPU/CA composite porous foam increased with the increase of casting solution concentration and the decrease of Na Cl particle size.When the concentration of casting solution is12%and the size of Na Cl is 150-212μm,the comprehensive performance of the three-dimensional porous composite foam is better.2.The three-dimensional TPU/d-CA porous composite foam was prepared by vacuum solution casting/particle leaching technology and deacetylation modification technology.The morphology,wettability,surface chemical composition,mechanical property and oil-water separation performance of three-dimensional TPU/d-CA porous composite foam were system studied by SEM,infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS),contact Angle measurement instrument,universal testing machine,and chemical oxygen demand(COD)digestion apparatus.The results showed that TPU/d-CA composite foam can be used not only as a water-removing material,but also as an oil-removing material only under gravity for a series of oil-water mixtures.The water fluxes and oil fluxes are up to 43000 L/m~2·h and 85000 L/m~2·h,respectively,and the separation efficiency is over 98%.It also can be used as adsorption material to absorb all kinds of oil,and the adsorption capacity of carbon tetrachloride can reach 34 g/g.In addition,it can selectively,quickly and continuously separate oil-water mixed solution with the assistance of peristaltic pump,and its separation efficiency is still up to 98%after 15 cycles.Based on the introduction of TPU material and special surface wettability,it has good mechanical properties and antifouling ability.These results indicated that three-dimensional TPU/d-CA porous composite foam has a broad application prospect in the field of oil-water separation.3.The three-dimensional TPU/d-CA/PDA/β-hydroxyl iron oxide(TPU/d-CA/PDA/β-FeOOH)porous composite foam was prepared by dopamine deposition and in-situ mineralization.The morphology,chemical composition,mechanical properties,wettability,oil-water separation and photocatalytic performance of TPU/d-CA/PDA/β-FeOOH porous composite foam were studied by SEM,FTIR,XRD,XPS,TGA,universal testing machine,contact angle measuring instrument,COD decomposition instrument and tester,and ULTRAVIOLET spectrum system.The results showed that TPU/d-CA/PDA/β-FeOOH porous composite foam has double superhydrophilic properties in air(both hydrophilic and oleophilic)and double hydrophobic properties in liquid(both underwater and underwater hydrophobic).Only under the action of gravity,the water removal flux of the composite foam is up to15000 L/m~2·h,and the water removal flux is up to 78000 L/m~2·h,and the oil-water separation efficiency is up to 99.4%.In addition,the composite foam showed strong photocatalytic activity and excellent photocatalytic cycling stability under the irradiation of visible light(sunlight).The degradation efficiency was 99.9%,98.4%,96.3%and 94.8%for methylene blue,rhodamine B,methyl orange and congored organic dyes only under 20min,20min,30min,38min and 45min,respectively.