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With the long-term use of coal bunker, a certain amount of sticking objects will be formed on its wall, and coal mine clearing robot can replace man in clearing the bunker wall. Also, since it equip with an explosion-proof camera, the worker can determine the operation by observing the well-head monitor. Moreover, it cannot work unless it is placed in position and supported stably, and it has three degrees of freedom: rotating, stretching, and shovel coal. It is driven by the hydraulic and controlled by PLC. The underground coal mine clearing robot changs the traditional clearing methods, man does not have to enter the bunker to clear it, which ensures the production safety of coal transportation.

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In this study, we proposed a novel and facile method to modify the surface of TiO2 nanoparticles and investigated the influence of the surface-modified TiO2 nanoparticles as an additive in a polyurethane (PU) coating. The hyperbranched polymers (HBP) were grafted on the surface of TiO2 nanoparticles via the thiol-yne click chemistry to reduce the aggregation of nanoparticles and increase the interaction between TiO2 and polymer matrices. The grafting of HBP on the TiO2 nanoparticles surface was investigated by means of X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), nuclear magnetic resonance (NMR) and thermogravimetry analysis (TGA). The thermal and mechanical properties of nanocomposite coatings containing various amounts of TiO2 nanoparticles were measured by dynamic mechanical thermal (DMTA) and tensile strength measurement. Moreover, the surface structure and properties of the newly prepared nanocomposite coatings were examined. The experimental results demonstrate that the incorporation of the surface-modified TiO2 nanoparticles can improve the mechanical and thermal properties of nanocomposite coatings. The results also reveal that the surface modification of TiO2 with the HBP chains improves the nanoparticle dispersion, and the coating surface shows a lotus leaf-like microstructure. Thus, the functional nanocomposite coatings exhibit superhydrophobic properties, good photocatalytic depollution performance, and high stripping resistance.

Talc was modified by aluminate coupling agent (ACA) before filling it into high density polypropylene (HDPP) to prepare talc/HDPP composites. Scanning electron microscopy (SEM), wear testing machine, electronic universal testing machine, and impact testing machine were used to analyze the surface modification and the effects of modified talc on friction and mechanical properties of modified talc/HDPP composites. The results indicate that after modified the lamellar structure of talc particles are open and the dispersion of particles are improved, and the edges and corners of surface become softer. Friction properties indicate that when the talc content is 8 wt%, both µ and K are at a lower value, which show that have better wear resistance. The frictional surface is relatively smooth and no furrow trace has found. Mechanical properties show that with talc content increasing, tensile strength and flexural strength of composites increase.