Study On Orientation Control Of Montmorillonite Under Magnetic Field And Gas Barrier Properties Of Montmorillonite/Bromobutyl Rubber Composites

The polymer/layered silicate nanocomposites have excellent barrier properties,and the study of the composites is also extensive.BIIR has excellent air tightness,widely used in tires,drug stoppers and other industries,but in some occasions it still needs to further improve the airtight,such as some toxic and harmful gas protective clothing.In order to enhance the barrier properties of BIIR,the magnetic MMT ordered BIIR composites were prepared by magnetic field induced magnetic MMT orientation in this paper.The permeability coefficient of the material was tested and compared with the magnetic MMT random composite materials.The mechanism of the barrier material to further reduce the permeability coefficient of the material was discussed,so as to provide the technology for the development of the airtight elastomer composite material support.Magnetic MMT was prepared by in situ chemical coprecipitation method by using MMT as the raw material,and the particle size of Fe₃O₄ nanoparticles on the MMT surface was about 20.15 nm.And then OTAB was used to be its organic modifier.The samples were analyzed by SEM,TEM,FTIR,XRD and thermogravimetric analysis.The results show that the thickness of MMT is about 25 nm and the diameter is about5?m,and the layered structure of MMT is maintained.After organic modification by OTAB,the hydrophobicity of MMT was enhanced,and MMT has the magnetic properties.The results show that the crystallinity of Fe₃O₄ in magnetic MMT is the highest at the reaction temperature of 60 ?.The results show that the magnetic MMT is the most active.And APTES can effectively enhance the binding force between Fe₃O₄ and MMT,while improving the agglomeration of Fe₃O₄ on MMT surface.The VSM test shows that the sample had good magnetic response properties.The minimum theoretical magnetic field strength Hmin required for the magnetic modification of MMT was calculated by using the Boltzmann statistic.The minimum theoretical magnetic field strength Hmin required for the magnetic modification of the MMT was calculated by using the ellipsoid shell model to analyze the stress and motion state of the single lamina under the applied magnetic field.The mixture and the BIIR latex mixture were placed in a horizontal magnetic field for curing,followed by leaching and vulcanization.The films were characterized by SEM and XRD.The results show that the magnetic MMT is aligned in the horizontal direction in the BIIR matrix.The results show that the helium permeability coefficient of the material can effectively reduce the helium permeability coefficient of the magnetic MMT,and when the content of the filler is 4%,its permeability coefficient is the lowest at 10.2cm3cm/m² dbar.