Preparation And Reinforcing Properties Of Coal-silica Dual Phase Filler

A kind of coal-silica dual phase filler was prepared by in-situ coating of silicic acid deriving from sol-gel method on the superfine coal particle,drying and dewatering,and surface modification.The microstructure and surface properties of the dual phase filler were characterized by SEM,FT-IR,Raman spectroscopy,XRD and contact angle meter.Reinforcing properties of the dual phase filler in styrene butadiene rubber?SBR?were also researched.The results show that the significant changes in the composition and microstructure of coal samples were observed after wet milling.When being ground for60 min,the D₉₈ of HN coal sample reached 5.38?m,coal particles are fully dissociated,the lamellar structure was very developed,the structure order degree decreased,and the surface functional groups were effectively released.At the reaction temperature of40?,pH=10,the volume ratio of tetraethyl orthosilicate to ethanol was 1:10,and the mass ratio of silicon dioxide to pulverized coal was 1:4,the particle size of silica reached nanometer level,the silica particles were evenly distributed on the surface of the coal particles,and the two paticles were closely combined.After being modified by10%hexamethyldisilazane at 60?,the contact angle of the modified dual phase filler increased to 91.23o,the polar groups on the surface of dual phase composite were significantly decreased,consequently the hydrophobic perfomance was enhanced,and the order degree of the layered particles was decreased.The dual phase filler showed good dispersion and compatibility in SBR composites,remarkably improved the cross linking density,the mechanical property and abrasive resistance,and decreased the rolling resistance of the SBR composites.The dual phase filler has good reinforcing effect in SBR composites.