TITLE:
Process Temperature Profile and Rheological Properties of Greases from Vegetable Oils
AUTHORS:
Leticia M. Lazaro, Donato A. G. Aranda
KEYWORDS:
Grease; Vegetable Oil; Acid; Rheology
JOURNAL NAME:
Green and Sustainable Chemistry,
Vol.4 No.1,
February
25,
2014
ABSTRACT: Greases are
composed by lubricating oil dispersed in a thickener that can be a metal soap,
polymers or clays. Grease production using vegetable oils is increasing due to
biodegradability requirements. Since vegetable oils present a worse oxidation
and hydrolysis stability than mineral oils, it is usually difficult to produce
a neutral grease
using them. Four greases were produced using soybean oil as lubricating oil and
lithium 12-hydroxy- stearate
as thickener. The maximum temperature of reaction ranged from 230°C to 120°C in a bench process and a reduction in the final product
acidity was observed (from 8.2% acid to 0.05% alkaline). Traditional tests to
evaluate thickener structure resistance like 10,000-time worked penetration, roll stability and
dropping point were performed and results compared. In addition, rheological
tests were performed and the results were also compared. Results indicate that
it is possible to produce a quite neutral grease using vegetable oils with good
thickener structure properties.