Advancements in Cellulose for Eco-Friendly Lubricant Applications: A Review on Tribological Properties.

Cellulose, a sustainable and biodegradable biopolymer, has emerged as a promising candidate for lubricant additives due to its ability to form protective boundary layers, reduce surface roughness, and enhance load-bearing capacity. This review explores the underlying tribological mechanisms, such as the mending effect, physical adsorption, and hydrogen bonding, which contribute to the performance of cellulose-based lubricants. Various applications are then discussed across liquid, semisolid, and solid lubrication systems. Notably, cellulose nanocrystals (CNCs) and hydroxyethyl cellulose (HEC) demonstrate strong friction and wear reducing performance. The paper also identifies some research gaps and limitations that need to be addressed.