Improving ester hydrolytic stability using triblock polyalkylene glycols

Abstract

Purpose

This paper aims to examine the role of different polyalkylene glycol architectures in improving the hydrolytic stability of natural and synthetic esters.

Design/methodology/approach

Hydrolytic stability measurements were conducted using a modified ASTM D2619 test method in which several polyalkylene glycol chemistries were examined at concentrations of up to 10 per cent in a selection of esters.

Findings

The inclusion of triblock copolymers derived from ethylene oxide (EO) and 1,2-propylene oxide (PO) and with an EO content of about 30 per cent produced significant improvements in the hydrolytic stability of natural and synthetic esters. Stability improved with increased concentration of the triblock.

Research limitations/implications

The study did not evaluate the vast array of polyalkylene glycol structures that can be derived from other higher alkylene oxides.

Practical implications

Improving the hydrolytic stability of esters can offer the possibility of creating longer life environmentally acceptable lubricants (EALs).

Social implications

This discovery should allow longer life EALs to be designed thereby using less raw materials over a determined period. It may also allow more replacement of conventional hydrocarbon lubricants.

Originality/value

Triblock copolymers are rarely used in lubricants. Their use as components of ester-based EALs is new.

Citation

Greaves, M.R. and Zaugg Hoozemans, E. (2018), "Improving ester hydrolytic stability using triblock polyalkylene glycols", Industrial Lubrication and Tribology, Vol. 70 No. 2, pp. 418-422. https://doi.org/10.1108/ILT-09-2017-0272