Metathesized palm oil & novel polyol derivatives: Structure, chemical composition and physical properties

Abstract

Metathesized palm oils are now a major source of fine chemicals; in particular due to the commercial production of 1-decene and 3,4-dodecene by cross metathesis of 1-butene and palm oil. This process results in the generation of a modified palm oil triacylglycerol (PMTAG) by-product, which has not been sufficiently studied. In this communication, the compositional analysis of PMTAG produced at a commercial scale is reported for the first time, and reveals that a percentage of the unsaturated fatty acids were shortened at the location of the double bond, producing a lower molecular mass TAG oil with terminal double bonds, and less steric hindrance compared to the natural oil. Furthermore, although PMTAG presented physical properties close to highly unsaturated vegetable oils, it retained a two-portion composition similar to palm oil, making its fractionation feasible with existing industrial methods. The epoxidation followed by hydroxylation of PMTAG resulted in a polyol comprising non-functional structures inherited from PMTAG and structures with diols, tetrols and hexols in which 50% of the hydroxyl groups were in terminal positions. The OH value (155mgKOH/g), thermal stability (∼370°C), melting profile (offset temperature ∼45°C) and viscosity characteristics qualify the PMTAG polyol as a suitable substrate for the manufacture of a variety of materials including waxes, cosmetics and polyurethanes.