Defibering Treatment And Application Of Sepiolite Group Minerals Materials

Sepiolite group minerals have excellent physical-chemical properties, and they form as fiber bundles because of their minerogenetic condition. There were few effective methods for defibering. Aiming at the above limitations, this work defibred fibers by means of comprehensive actions of acid, surface active agent, high speed decentralization, ultrasonic oscillation, and airflow crushing. By microstructure characterization, fibers are well-defibred obviously after defibering treatment.The exterior wall heat-insulated coating with excellent properties was prepared by using the acrylic emulsion as matrix, defibred sepiolite fibers and glass hollow microspheres as main functional additives. It could arrest heat transmission and reflect visible light effectively. The optimum contents of additives are: glass hollow microspheres 6%, couple-agent treated defibred sepiolite fibers 8%. At the same time, a satisfactory testing device about thermal insulation effect was made by us. By modeling, thermal insulation properties of sepiolite fibers were improved significantly after defibering treatment. This result was in good agreement with the experiments.Polypropylene/attapulgite composites were prepared by melt blending, in which polypropylene was used as polymer matrix and attapulgite as inorganic components. The couple-agent modification of attapulgite was introduced in detail and the relation between structure and properties of polypropylene/attapulgite composites was mainly studied. The characterization on structure of polypropylene/attapulgite composites indicated that after modified by couple-agent,the dispersity of attapulgite in the polymer matrix was improved. The results of mechanical properties showed that mechanical properties of composites were improved generally because of the addition of modified attapulgite. At the same time, the optimum conditions of attapulgite modification for surface free energy of attapulgite and impact ductility of composites were deduced respectively by orthogonal range analysis.