Preparation and properties of cellulose/SiO2 grease
[Objective]With the increasing depletion of petrochemical resources and the environmental pollution caused by the extraction and use process,sustainable and environmentally friendly lubricating grease products have been prepared using renewable natural cellulose as a thickener.[Method]Three sets of lubricating grease products with a viscosity grade of 2# were prepared using pure cellulose,gas-phase SiO2,and cellulose/SiO2 as thickeners,and their penetration,drop point,oil separation rate,rheological properties,and tribological properties were tested.[Result]The silicon hydroxyl groups on the surface of SiO2 can undergo hydrogen bonding crosslinking with the hydroxyl groups of cellulose,improving the physicochemical properties,rheological properties,and tribological properties of lubricating grease.In terms of physicochemical properties,compared to cellulose grease and SiO2 grease,cellulose/SiO2 grease has a lower oil separation rate and improved colloidal stability;And a drop point appeared at 327 ℃,which improved the fluidity at high temperatures of silicone grease.In terms of rheological properties,the viscosity temperature performance and shear resistance of cellulose/SiO2 lubricating grease have been improved,and the structural recovery speed is faster than that of silicone grease,and the structural system is more stable.In terms of tribological performance,compared to cellulose grease and SiO2 grease,cellulose/SiO2 grease has an improved friction reduction effect,with the lowest friction coefficient and friction force.[Conclusion]A cellulose based grease with practical prospects has been obtained,which is in line with the national low-carbon and sustainable development strategy.[Ch,7 fig.2 tab.32 ref.]