Papers by Keyword: Polyorganosiloxane

Abstract: The paper deals with modern designs of crankshaft bushings used in internal combustion engines. It delineates the prospects of polymer coatings to ensure additional protection of lead bronze bushings in the event of emergencies associated with a temporary loss of lubrication. For this purpose, a polymer composition of silicone polyorganosiloxane and fluoro-epoxy lacquers is proposed. Tribotechnical results are provided for polymer-coated bushings: 1) in a full-film lubrication condition, 2) in boundary conditions (with lubricant residues once the unit has been switched off) and 3) in dry conditions (with no lubrication after a long standstill). A thin-layer (3...5 μm) polymer coating based on polyorganosiloxane and fluorine can be used on the bearing surfaces of the shells of highly loaded bearings in order to increase antifriction properties, especially with limited lubrication and possible scores in a bearing.

Abstract: The polyorganosiloxane superhydrophobic film was fabricated via a sol-gel process followed by nano-silica(SiO₂) sol and new organo-siloxane reagent 1,1,1,3,5,5,5-heptamethyl-3-[2-(trimethoxysilyl)-ethyl]-tri-siloxane(in brief as HPTETOs), the chemical structure of the polyorganosiloxane superhydrophobic were described by Fourier transform infrared spectroscopy (FT-IR), the superhydrophobic property of the treated sample was measured by contact angle (CA) measurements. It revealed that nano-silica and polyorganosiloxane formed 3D hydrophobic groups on the film; the film has turned its wetting property from hydrophilic to superhydrophobic with water contact angle of 143.7°.

Abstract: Here we reported that the Si-O-C nanoballs (SCONBs) were yielded from polyorganosiloxane, polydimethylsiloxane, by chemical vapor deposition (CVD) method. The composite nanoballs with a range of diameters from 50 to 200nm were composed of silicon, carbon and oxygen based on analysis of EDX. At the transmission electron microscope(TEM) and scan electronic microscope(SEM), two populations of nanoballs were found: around 200nm and 500nm. X-ray diffraction patterns demonstrated that the nanoballs were dominatingly amorphous. Temperature played an key role in size distribution of Si-O-C nanoballs, and the 850–900°C temperature range was typical for nanoparticles growth via CVD.

Abstract: In this work, PDMS modified PU was synthesized using two-stage method to improve water resistance and weather resistance in the waterborne polyurethane was investigated. It was found that the absorbed water content decreased with increasing PDMS content in polyurethane. It was also found that PDMS modified polyurethane had better solvent resistance than unmodified polyurethane. The structure incorporated the PDMS into the soft segment of polyurethane chains was confirmed by FTIR. The phase separation increased by increasing PDMS content and was confirmed by DSC. The particle size of the dispersions increased and tensile strength and hardness decreased with the increase of PDMS content. Furthermore, with the improved water resistance and elongation, it was hoped that the modified polyurethane could be used as wood coatings superior to the solvent-borne systems.