Study On Preparing Modified-Bentonites By Microwave Radiation And Its Application

In order to receive high quality modified-bentonite, improve production efficiency and reduce production cost, a new method for preparing Na-bentonite and organobentonite by microwave radiation was put forward. In this paper, high capability organobentonites have been synthesized by quaternary ammonium as organic-modified reagent using the sodium bentonite, which are purified and modified from bentonites by microwave dry process. The properties and structures have been investigated as well by X-ray diffraction, infrared absorption spectrum and differential thermal analysis. The solvent dilatability and gelation ability, viscidity and organic content have been tested. At the same time, preparation process and product structure by microwave radiation were compared with these by tradition heating respectively. Finally the nanocomposite of epoxy resin with organobentonite was prepared and the organobentonite has been used for the modifying reagent of epoxy resin. The structure of composite material was characterized by infrared absorption spectrum, and then its mechanical properties were examined.The results show that new sodium modification and organic modification methods can shorten not only experimental manipulation time, simplify reaction process, and reduce energy consumption and production cost, but also receive high quality Na-bentonite and organobentonite which may satisfy these requirements of all industries application. High quality sodium bentonites and organobentomtes are obtained by microwave dry process and the factors that affected their synthesis are investigated respectively. The optimum process conditions of sodium bentonites and organobentomtes were obtained by optimizing experiment with using orthogonal table. The structure analysis by X-ray diffraction, infrared absorption spectrum and differential thermal shows that the structures of Na-bentonite and organobentonite prepared by microwave radiation in the best condition are almost the same as that by tradition heating, so sodium modification and organic modification by microwave radiation were successful. The biggest crystal layer distance of Na-bentonite and quaternary ammonium organobentomtes is higher than 9 angstrom and 20 angstrom respectively. The analysis of organobentomtes' capability shows that the organic losing rate of baked organobentonite is between 27 to 40 percent, and the viscidity of the octadecyltrimethyl ammonium organobentonite prepared by microwave radiation is 1180 mPa-s. In addition, the organobentonite has good solvent dilatability and gelation ability in the organic medium. Finallythe preparation of organobentonite/epoxy nanocomposites shows that its properties were optimal, as the content of the organobentonite was about 1wt%. Compared with pure epoxy resin, the flexural strength rose 6%. Meanwhile the fundamental mechanism need to be studied further.