A novel green and low friction composite reinforced by lignum vitae chips

Lignum vitae was widely applied in water-lubricated bearing because of its green, pollution-free, excellent mechanical, and self-lubricating properties. The slow growth cycle is difficult to meet the bearing's rapid development. Lignum vitae chips were used to modify thermoplastic polyurethane (TPU) to extend its good selflubricating properties and improve tribological behaviors. The results showed that lignum vitae improve TPU's shore hardness, elastic modulus, and elongation, but at the slight cost of tensile strength and thermal stability. Besides, lignum vitae chips endowed TPU with good hydrophilicity and water absorption properties, which conduced to form effective lubricating film and reduced COF behaviors. TPU with 6% lignum vitae chips had the best COF reduction and wear resistance. But excessive lignum vitae chips weakened elastic modulus and elongation to increase COF behaviors and wear process. The outcome obtained herein would provide strong theoretical guidance for developing novel green and sustainable composites with excellent tribological properties.

Automated summary

The study found that lignum vitae chips can improve the properties of thermoplastic polyurethane, such as hardness and elastic modulus, and reduce the coefficient of friction and wear. However, adding an excessive amount of lignum vitae chips leads to a decrease in material elasticity and elongation, and an increase in the coefficient of friction and wear.