Preparation and properties of cellulose isocyanate based lubricating grease

With the increasing depletion of petrochemical resources and the improvement of people's awareness of environmental protection, the green and sustainable development of grease is extremely urgent. In this study, environmental-friendly cellulose-based lubricating grease was prepared by surface isocyanate modification using natural and renewable microcrystalline cellulose as raw material. The grafting effect on the surface of cellulose was analyzed using FTIR, SEM, XRD, and TG methods. The rheological and tribological properties of cellulose based lubricating grease were studied using a rheometer and a four ball tribotester. The research results indicate that after modification with isocyanate, cellulose greatly improves its thickening ability on base oil. Compared to pure cellulose-based grease, the shear resistance of modified cellulose-based grease has been improved, and the critical point and flow point are significantly increased. Moreover, the two types of lubricating greases exhibit similar viscoelastic laws, with a linear viscoelastic function decreasing with increasing temperature in the range of 0-50℃; In the range of 50-100℃, the linear viscoelastic function increases with increasing temperature. The wear resistance of modified cellulose-based grease has been improved, and the wear spot diameter has decreased from 0.873 mm to 0.820 mm.