Synthesis And Properties Of PdDCPD/Inorganic Nanoparticals Composites

First, dialkyidithiophosphate (PyDDP) was used as the stabilizing agent and coating agent, sodium molybdate as moly source, sodium sulfide as sulfur source, vis surface coating technology, molybdenum disulfide(MoS₂) nanopowder and copper sulfide(CuS) nanopower coated by PyDDP were prepared by liquid phase reduction and liquid precipitation reaction, respectively; then molybdenum disulfide(MoS₂) nanopowders and copper sulfide (CuS) nanopowers coated by PyDDP were used as the additives of polydicyclopentadiene, and Bi-component catalyst system (WCl6 and Et2AlCl) were adoped for the polymerization of dicylopentadiene(DCPD). The best reaction condition was determined by ampule tests. Based on the amoule tests, PDCPD/MoS₂ nano-composite and PDCPD/CuS nano-composite were prepared by in-suit polymerization in our self-made RIM device.Dispersion test, Infrared spectrum (FT-IR), X-ray diffraction (XRD) and Transmission electron microscope (TEM) were employed to characterize the dispersion in the dicylopentadiene (DCPD), structure, and morphology of the MoS₂ and CuS nanopowders; The morphology, structure, mechanical properties, and tribological properties were characterized and tested by FT-IR, XRD, Thermogravimetric analysis(TG), SEM, universal material testing machine, and high-temperature atmosphere friction/wear tester.The results showed that PyDDP had been successfully introduced into the surface of MoS₂ and CuS nanopowders, and the homogeneous dispersion of MoS₂ and CuS nanopowder in DCPD monomer were successfully achieved, when the amount of the nanopowders reached 3% (mass fraction) in DCPD, nanopowers could still stay in the DCPD for more than one month; The best reaction conditions of in-situ polymerization of DCPD and nanopowders, which were determined by ampule tests. The polymerization temperature was 80℃, and the mole ratio of n(DCPD):n(W):n(Al) was 1200:1:25. The results of XRD showed no characteristic diffraction peaks of MoS₂ and CuS nanopower existed in nanocomposites, compared to the XRD of PDCPD, PDCPD/MoS₂ nanocomposites and PDCPD/CuS nanocomposites had the similar diffraction peak, which implied that PDCPD/MoS₂ nanocomposites and PDCPD/CuS nanocomposites had the similar structure with that PDCPD, and crystalline and amorphous structure coexisted in the nanocomposites. The stress-stain curve showed that the fracture mode of the two nanocomposites were tough fracture. Compared to the pure PDCPD, the mechanical properties and tribological properties of PDCPD/MoS₂ nanocomposites and PDCPD/CuS nanoposites at the range of low additive amount of nanopowers were both enhanced. When the content of nanopowers was 1%, the PDCPD nanocomposites showed the best comprehensive properties. When the content of MoS₂ nanopowers was 1%, compare to the pure PDCPD, the tensile strength of PDCPD/MoS₂ nanocomposites increased by 38%, the impact strengh increased by 14% , the bending strength increased by 28% and the friction and wear mass were reduced by 44% and 40% , respectively; When the content of CuS nanopowers was 1%, compare to the pure PDCPD, the tensile strength of PDCPD/ CuS nanocomposites increased by 19%, the impact strength increased by 14%, and the bending strength increased by 14%. ]...