Uhmwpe Cell Membrane Forming Research

The ultra-high molecular weight polyethylene is a resin which hasexcellent, has physical,chemical and mechanical properties,and low price.Ithasbeen widely used in various fields. In this paper, the sintering method, meltextrusion method, thermally induced phase separation method are used inultra-high molecular weight polyethylene film forming.And UHMWPEmembrane surface is modified.Sintering of ultra high molecular weight polyethylene film: scratchUltra-high molecular weight powder on the surface of the template.Place it inthe oven for sintering. Gap is left between the powder particles after sinter.However, due to the powder particle size is too large, membrane pore size istoo large to the require of the cell membrane aperture.The experiment failed.Melt extrusion ultrahigh molecular weight polyethylene film: usingparaffin as a diluent to improve the processing performance of ultrahighmolecular weight polyethylene. Twin-screw is used in extrusion. First, mixparaffin and silica in the high-speed mixer so that the paraffin is coated on the silica surface,then, mix with high molecular weight polyethylene. The mixtureis processing buy the twin-screw extrusion to be film. Extract the paraffin ionwith low boiling point solvents from the film, then dry it. The film made bythis method can meet the requirements of the cell membrane,such asmembrane pore size, porosity, mechanical properties. But the film is too thick.Improving the equipment can not make the film reach the lithium-ion batterymembrane requirements. But the film can be applied to a number of otherbatteries.Thermally induced phase separation of processing ultra-high molecularweight polyethylene film: ultrahigh molecular weight polyethylene can bedissolved by paraffin under the heat and shear of a twin-screw,then isprocessed to be film.The film is cooling and the solid-liquid phase separate atthe same time. The membrane is finished after extraction paraffin from thefilm. Paraffin is remained in the crystal or between crystals. The gaps areformed after the extraction of paraffin.This film can meet the requirements ofthe cell membrane,such as membrane pore size, porosity, water flux andmechanical properties. But the membrane is poor at hydrophilic.In order to improve the hydrophilicity of the membrane, the thermalinitiation, and ultraviolet light initiation has been used. A variety of monomersare used in surface grafting modification of the membrane. Experimentalresults show that:The modified effect of ethyl acrylate and butyl acetate in the two trigger methods are excellent. The effect of heat-induced is better, but itsprocess is cumbersome and time-consuming than the UV irradiation. UVirradiation is more suitable for industrial production.