Study On The Tribological Property Of Nylon1010 Filled By Modified Mineral

The interface bonding of polymer matrix composite was considered as the key factor of tribological properties. In this paper three kinds of polymer composites were prepared, by filling hard spiculate wollastonite with SiO₂ and TiO₂ nano-coating and soft flaky graphite with SiO₂ nano-coating into nylon 1010 respectively. The effect of nano-coated layer on interface bonding was investigated, as well as the mechanism of effects on tribological behaviors of the composites was discussed.The nano-coatings were characterized by scanning electron microscope(SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), respectively. The mechanical and tribological properties of composite containing different filling amount were investigated. Furthermore, the aggregate state structure, thermal stability, topography of wear surface and cross section were analyzed by XRD, differential scanning calorimeter (DSC),thermogravimetry(TG), SEM and microscopy, respectively. The main conclusions were drawed as following.The composites obtained high interface bonding strength after filled with TiO₂-coated wollastonite,SiO₂-coated wollastonite, and SiO₂-coated graphite, which induce nylon 1010 crystallization.Although nylon 1010 filled with TiO₂-coated wollastonite could decrease the friction coefficient, the wear rate of composite is still higher than that of nylon 1010 filled with wollastonite, because of chemical wear due to the catalysis activation of TiO₂ coating layer during thermal decomposition of nylon substrate. However, further stearic acid treatment of TiO₂-coated wollastonite surface could help to increase crystallization of nylon 1010, decrease the catalysis activation of coated layer, thus restrain chemical wear and decrease both friction coefficient and wear rate. Graphite with SiO₂ coating could increase the interface bonding strength, help to the formation of transfer film and increase the thermal stability, resulting in the smaller coefficient and lower wear rate of composite. Graphite with SiO₂ coating by silicone coupling could further decrease the wear rate of composite, but increase the friction coefficient. The composite with 30% graphite under different treatments has worse wear resistance than nylon 1010, due to bad shear resistance of graphite.Wollastonite with SiO₂ coating could induce the crystallization of nylon and increase the thermal stability of nylon matrix, thus resulted in low friction coefficient and wear rate. In comparison with being filled wollastonite, friction coefficient and wear rate of composite filled with 20% SiO₂-coated wollastonite decreased by 43.3% and 81.2% respectively. And friction coefficient and wear rate of composite filled with 20% wollastonite with SiO₂-coated after silicone coupling decreased by 28.1% and 41.7% further.All of the results suggested that the tribological mechanism of nylon 1010 filled with nano-coating was as following. Nano-coating could induce crystallization of nylon 1010. On the one hand, improved crystallization increases the interface bonding strength and is beneficial to the formation of transfer film, which resulted in the decrease of friction coefficient. The other hand, coating has effect on the thermal stability of nylon matrix, which could significantly affect the wear rate. Futhermore, coupling treatment increased interface bonding strength of nylon 1010 filled with coated particles and decreased the wear rate. And the friction coefficient depends on the crystallinity of nylon matrix in the composite.