Effect of an alkali treatment on the development of cellulose pulp-based gel-like dispersions in vegetable oil for use as lubricants

• Published in: Tribology international 2018-07, Vol.123, p.329-336
• Main Authors: Martín-Alfonso, J.E., López-Beltrán, F., Valencia, C., Franco, J.M.
• Format: Article
• Language: English
• Subjects: Alkali treatment; Alkalies; Biodegradability; Caustic soda; Cellulose; Cellulose pulp; Dispersions; Gel-like dispersion; Greases; Lithium; Lubricants; Lubricants & lubrication; Lubricating greases; Lubrication; Rheological properties; Rheology; Sodium hydroxide; Tribology; Vegetable oils
• ISSN: 0301-679X; 1879-2464
• DOI: 10.1016/j.triboint.2018.02.027

The main aim of this study was to elucidate the influence of an alkali treatment on the rheological and tribological properties, and microstructure, of cellulose pulp-based gel-like dispersions potentially usable as biodegradable lubricating greases. For this purpose, cellulose pulp was treated with sodium hydroxide under different conditions of alkali concentration (20, 30 and 40%), temperature (20, 45 and 75 °C) and contact time (1 and 2 h). Favourable conditions relative to the rheological response of a commercial lithium lubricating grease used as benchmark were found to be 40% NaOH, 20 °C and 2 h. Gel-like dispersions with acceptable lubrication properties in terms of consistency indices, mechanical stability, and frictional and wear performance, were obtained by using a 6–7% (w/w) proportion of cellulose pulp. •Development of cellulose pulp-based gel-like dispersions in vegetable oil.•The role of alkali treatment on the rheological and tribological properties.•Effective method for improving the compatibility of fibres and vegetable oil.•Comparative study with a commercial lithium grease.