Alkyl glyceryl ethers as water –based lubricant additives in mixtures with xanthan gum

Abstract Water-based lubricants are greener and more environmentally friendly than comparable oil-based lubricants. However, water-based lubricants typically have a poorer performance and, thus, need to be formulated with various additives. Here, alkyl glyceryl ethers, a class of nonionic surfactants, were investigated as lubricant additives. To this purpose, aqueous solutions of newly synthesized ethers (with different alkyl chain lengths, C8, C10, C12, and C14) were formulated with xanthan gum. The lubrication performance of these formulations was then tested experimentally. Clearly, alkyl glyceryl ethers showed a significantly improved performance (higher friction reduction) with increasing the alkyl chain length. However, the ethers had to be formulated with xanthan gum, with which they formed a complex, which promoted ether dispersion and probably adsorption on the metal surface in the aqueous phase, thereby drastically reducing friction. Thus, the alkyl glyceryl ethers synthesized in this work are attractive green and highly efficient lubricant additives, which can improve the sustainability of industrial lubrication processes.