Preparation And Research Of Biodegradable Polylactide Three-dimensional Porous Oil Absorbing Materials

With the rapid development of the global economy,the oil pollution problems caused by industrial wastewater,domestic wastewater and marine oil spills are becoming more and more serious,and the harm to environment and human health is even worse.Now the polypropylene melt-blown nonwovens and synthetic polymers porous materials such as polyurethane foam using molding method were widely used in oil-absorbing field.these materials have good oil absorption properties,but they had some weaknesses: being eas ily polluted,being not biodegradable,no reusability,and being not conducive to the ecological environment.This paper focused on the fabrication of biodegradable three-dimensional porous oil absorption materials using biodegradable polymer mater ials as raw material,as well as the characterization and evaluation of the structure and oil absorption properties of the materials by SEM?DSC?FTIR.To realize the properties of rapid oil absorption,biodegradation and reusability,we chose the biodegradable polymer material---polylactic acid(PLA)and the natural fibers---kapok fiber which is degradable and abundant as the main raw materials,then prepared the three-dimensional porous materials using non-solvent induced phase separation,finally dried under the vacuum condition at room temperature.The main experimental designed and the properties were as follows:(1)We studied the phase separation process of polylactic acid porous materials,concluded that non-solvent ratio,polylactic acid concentration,and phase separation temperature all had influence on the pore structure.The results showed that,low standing temperature and low polymer concentration could drastically decrease the density of material,and increase the porosity and oil absorption rate.Through the contact angle test,we came to conclusion that water contact angle was about 130 degrees,while the oil contact angle was just about 0 degrees.(2)We prepared polylactic acid / kapok fiber composite porous material,and studied the effect of kapok fiber on the oil absorption properties of materials.The porous materials were characterized by different test instruments,The results indicated that,the incorporation of kapok fiber increased the oil absorption rate and oil absorbency of polylactic acid / kapok fiber composite porous material,but the porosity decreased.(3)We prepared polylactic acid / kapok fiber composite macroporous material using salt leaching method,and prepared polylactic acid /polycaprolactone blending mater ial,then studied the effect of material pore size and elasticity on oil absorption performance.We could find that,the macroporous size significantly increased,just about 20~50um.In addition,there are a lot of mesoporous on the wall of pores.The polylactic acid/kapok fiber/salt leaching porous materials exhibited rapid oil absorption rate and excellent oil absorbency,which is up to 12g/g~17g/g.What's more,the kapok fiber reinforced the strength so that the morphology of material didn't deform after repeated use.These porous materials were green biodegradable efficient absorbents that should be useful for the treatment of oil spills.