Preparation Of Residual Oil-based Polymer Nanocomposites And The Investigations Of Their Friction And Wear Properties

At present,high temperature,pressure,salt and corrosive conditions dominate in deep,unconventional and complex formation.In these formation exploration and development using horizontal well and complex well techniques,the heavy friction,wear,lubricant failure or even the engineering failure often occur to the most popular metal machine,pipe and casings.Developing high-performance protective materials including polymer composite material with excellent physical chemical properties are specially required.In the paper,three kinds of polymer nanocomposite materials were prepared,which were used as protective materials for metals.Their thermostability,mechanical and wear properties were investigated.The main research results were as below.First of all,the condensed polynuclear aromatic?COPNA?copolymer was prepared from the aromatics of residual oil.Fourier infrared spectrum?FTIR?,scanning electron microscope?SEM?,thermogravimetric analysis?TGA?and their mechanical measurements were applied to characterizing the structures and properties of the copolymer resin.FT-IR results showed that ene reaction occurred between diphenylmethyene bismaleimide?BMI?and ACOPNA?allyl COPNA?,and their cross-linking reaction further happened during the curing process.The cured copolymer resin had smooth surface but wasn‘t dissolved in common solvent.TGA and mechanical test results indicated that mechanical property and thermal stability of the COPNA were obviously enhanced by the copolymerization modification.Secondly,montmorillonite?MMT?,SiO₂,and magnetic MMT nanomaterial,and their residual oil-based nanocomposites were successfully synthesized.X-ray diffraction analysis?XRD?,SEM and transmission electron microscopy?TEM?were applied to characterizing the structures and properties of nanocomposite and the dispersion of nanoparticles.The results showed that the tunable nanoparticle dispersions improved the mechanical and wear as well as thermal properties of the nanocomposite at 0.5-2.0 wt.% nanoparticles load.The aggregations of the nanoparticles slight made their whole property deteriorated at more than 3.0% nanoparticle load.Thirdly,poly?allyl condensed polynuclear aromatic-bismaleimide?/magnetic montmorillonite?ACOPNA-BMI/M-MMT?nanocomposite were prepared,and their friction and wear mechanism were investigated.It was found their friction coefficient and wear rate were varied along with pressure load,rotate speed and temperature.As the temperature increased to the critical level,the friction coefficient significantly reduced under the dry wear conditions.In addition,the friction coefficient decreased obviously as the load and rotate speed increased at the high temperature.In the test,abrasive dusts were produced and adhered to the surface of the metal,resulting in forming transfer film,which avoided the direct contact between composite and metal in order to reduce the wear rate of the composite.Such nanocomposite samples have better salt-tolerance at 2 wt.% M-MMT load.The nanocomposite surface,weight and thickness kept nearly unchangeable in the high salinity drilling fluid.The nanocomposite friction coefficient in the drilling fluid was much lower than that of dry friction under the same working condition,but its values of wear rate was much higher.In a word,these residual oil-based nanocomposites with excellent properties,such as thermostability,salt tolerance,friction and wear and mechanical properties,can protect casings pipes working in the extreme environment.