Fundamental Structure–Function Relationships in Vegetable Oil-Based Lubricants: A Critical Review

作者：Navindra Soodoo, Laziz Bouzidi, Suresh S. Narine · 发表于：Lubricants · 年份：2023 · DOI：10.3390/lubricants11070284 · 被引用次数：35 · 研究领域：Lubricants and Their Additives、Biodiesel Production and Applications、Phase Equilibria and Thermodynamics

Vegetable oil (VO)-based lubricants are environmentally friendly replacements for mineral oils. This work critically reviews the literature and identifies the molecular structures in VO-based lubricants which have been used to improve performance. The specific roles that size, type, number, position, spatial arrangement, and symmetry play in determining lubricating functionality were highlighted. Data were systematically collected to identify the contributions of major structural components and relate them to specific physical functionality measurables. The relationships were presented to reveal structure–function trends. Empirical predictive relationships between flow and thermal transition properties and structures were established. Molecular mass was revealed to be a fundamental determinant of viscosity and transition temperatures, but these properties were shown to also be influenced by other structural factors such as polar functional groups, branching, and symmetry. Almost all the examined viscosity data plotted versus molecular mass are enclosed within the 95% prediction band of an exponential rise to a maximum function (R2 = 0.7897). Generally, for both flow and thermal transition, a given structure versus function follows simple linear or exponential functions with unbranched VO-based lubricants, lending themselves more easily to strong correlations. This review is a first step towards comprehensively relating structure to lubrication function. The revealed relations...