Study On Polymerization And Capability Of Pmma/coal Series Kaolin Nanocomposites

In recent years, polymer-layered silicate intercalation nanocomposites have attracted a great deal of attention in material science. Most of the polymer-layered nanocomposites exhibit remarkable improvement in mechanical properties, heat resistance, and other properties because the silicate lamellar dispersed in the polymer matrix with nano-scale dimensions. Kaolin, a clay mineral with layered structure is a kind of natural nanophase materials. It has a broad application prospects because it is rich in natural resources and low in price. There is abundant high quality coal series kaolin in Inner Mongolia. The low utilization of coal series kaolin causes serious waste and environmental pollution. In this paper, the coal series kaolin is intercalated in order to prepare the PMMA nanocomposite. Not only studied modification of the PMMA nanocomposites and improving its properties, but also expanded the application range of the coal series kaolin.The kaolin was intercalated with DMSO by two methods. One was stirring in solution, and another was ultrasonic. Influencing factor of intercalation process was investigated by means of the rate of intercalation. XRD and FT-IR showed that kaolin had been inserted DMSO between the layers of kaolin. The basal spacing of kaolin intercalated by stirring in solution increased to 1.08nm, and the rate of intercalation was 83%.The potassium acetate was used to intercalate coal series kaolin by dry approach. The basal spacing increased to1.36nm, and the rate of intercalation was 79.6%.The poly(methyl methacrylate)/coal series kaolinite nanocomposite was prepared by bulk polymerization. The coal series kaolinite which was used in polymerization was intercalated by two different intercalation reagents. The mechanical, surface hardness, resistance to water absorption and thermal properties were tested. The structure of PMMA/coal series kaolinite was examined by XRD and scanning electron microscope.The results showed that the tensile property of nanocomposite was descent with the increase of coal series kaolinite content. The surface hardness test showed an increase to 2H as the amount of kaolinite between 3%-5%. PMMA nanocomposite with 5%DMSO intercalation coal series kaolinite reduce the rate of absorption water to 0.46%, decreased by 38%.The same effect of KAc intercalation coal series kaolinite was also detected. When the content was at 3%,the rate of absorption water cut down to 0.52, decreased by 30%.Thermal stability of KAc intercalation kaolin/PMMA nanocomposite exhibited remarkable improvement. DSC showed an increase of 18℃in the glass transition temperature. Compared with the two kind of intercalation coal series kaolin nanocomposite, KAc intercalation coal series kaolin/PMMA was better than DMSO intercalation coal series kaolin/PMMA. XRD and SEM showed that kaolin/PMMA formed partially exfoliated nanocomposites in the presence of 10%DMSO intercalation kaolinite, and the 10%KAc intercalation kaolin/PMMA had better exfoliate effect.