Lignin-amino acid based new green lubricants enabled by reciprocal hydrogen bonding

Project team: Paul Christakopoulos, Leonidas Matsakas, Ulrika Rova

Partners: Yijun Shi (project Leader), Machine Elements, TVM, LTU

Duration: 2020-2023

Funded by the Swedish Research Council (VR)

Existing lubricants are heavily relied on petroleum products, which causes a series of environment problems such as soil contamination, water pollution and others. In the proposed project new type of green lubricants based on lignin and amino acid will be developed and evaluated. The objective of this project is to understand the tribological behaviour of green lubricants with the involvement of a new type of molecular interaction called reciprocal hydrogen bonding (rcp-HB) and provide a sustainable solution to existing petro-lubricants. The hypotheses of the research are: 1) introducing rcp-HB between lignin and amino acid based ionic liquids (AA-ILs) could enhance their interactive bonding and therefore lignocellulose dissolution in AA-ILs; 2) rcp-HB promotes the adhesion of lignin/AA-IL to friction surface, toughens lubrication film and improves boundary lubrication. The effect of the molecular structure of AA-ILs and the surface modification of lignin on the solubility of lignin and the lubricants performance will be systematically investigated. Unveiling the relationship between rcp-HB and lignocellulose dissolution will provide intellectual guidance and effective tool for wider range of biomass utilization. The findings of lignocellulose chemistry in lubrication will enlighten the exploration of sustainable products and processes for engineering systems.