Development of environmentally friendly lubricant using natural resources: Layered double hydroxide gels

The development of a sustainable and environmentally friendly alternative to petroleum-based lubricants is a major challenge. In this study, layered double hydroxide (LDH) vegetable oil gels were prepared from stearic-acid-intercalated LDH (LDH-SA) and vegetable oil. The effects of content of LDH-SA and types of vegetable oils on the rheological properties of the gels were studied. The effects of several plant-derived antioxidants on the oxidative stability of LDH-SA gels were also investigated. Further, the tribological properties of LDH-SA gels were studied and compared with those of a lithium grease under the same conditions. The results showed that LDH-SA gels exhibit the typical rheological properties of grease, such as viscoelasticity, shear thinning, and structural thixotropy . Tocopherols , tea polyphenol, gallic acid , and their combinations can enhance the oxidative stability of LDH-SA gels. The tribological experiments showed that LDH-SA gels maintained the inherent excellent tribological properties of their corresponding vegetable oil. LDH-SA gels provide a new idea for the development of environmentally friendly lubricants.