| In this paper, the nanometer-sized silica was organically grafted with TDI and ethylene glycol monobutyl ether, or by treated with silicohydride coupling agent (K.H-560). The vermiculite was organically modified using hexadecyl trimethyl ammonium bromide (CTAB) and KH-560, respectively. The above inorganic particles in various content were introduced to the phenolic resin through in-situ polymerization method. The distribution of the nanometer-sized particles in the resultant materials, thermal stability and other corresponding properties were characterized. Moreover, the friction and wear performance of the brake pad based on the developed nanocomposites were also investigated.The results of FT1R showed that the organic modifiers have been bonded to the nano-silica and vermiculite. The XRD spectrum results indicated that the organic modifiers were intercalated into vermiculite layers, broadening the interlayer spacing. AFM tests illustrated that the modified nano-silica and vermiculite were dispersed into the PF matrices uniformly. The nanometer-sized silica particle in the nanocomposites possessed the diameter in a range of 70~ lOOnm, and the vermiculite layers were exfoliated fully or partly. The tlow distance and gelating time of the nanocomposites were shorter than that of the pure PF, which meet the standard of the PF used in frictional materials. Compared to the pure PF, the silica7PF nanocomposites exhibited excellent heat stability only in nitrogen atmosphere, however, so do vermiculite/PF nanocomposites in both nitrogen and air atmospheres.Compared to the brake pad based PF resin, the wear rate of the present one based with silica/PF nanocomposite decreased obviously, especially in high temperature. Additionally, the brake pad based vermiculit/PF nanocomposites are also improved in the wear performance. A preferential stable friction was achieved for a brake pad based a KH-560-vermiculite/PF nanocomposile, which can be served as a high performance frictional materials.
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