文摘
Vegetable oils have significant potential as a base fluid and a substitute for mineral oil in greaseformulation. Preparation of soybean oil-based lithium greases using a variety of fatty acids in thesoap structure is discussed in this paper. Soy greases with lithium-fatty acid soap having C12-C18chain lengths and different metal to fatty acid ratios were synthesized. Grease hardness wasdetermined using a standard test method, and their oxidative stabilities were measured usingpressurized differential scanning calorimetry. Results indicate that lithium soap composition, fattyacid types, and base oil content significantly affect grease hardness and oxidative stability. Lithiumsoaps prepared with short-chain fatty acids resulted in softer grease. Oxidative stability and otherperformance properties will deteriorate if oil is released from the grease matrix due to overloading ofsoap with base oil. Performance characteristics are largely dependent on the hardness and oxidativestability of grease used as industrial and automotive lubricant. Therefore, this paper discusses thepreparation methods, optimization of soap components, and antioxidant additive for making soy-based grease.Keywords: Vegetable oils; Li-grease; NLGI hardness; oxidative stability