Combining biocatalysts to achieve new phase change materials. Application to non-edible animal fat

Abstract

The thermal properties of various alkyl threo-9, 10-dihydroxystearates (DHSEs) prepared from non-edible fat were studied. Non-edible animal fat was hydrolyzed in a 93% yield with R. oryzae resting cells. Crude unsaturated fatty acids were recovered from the matter liquor resulting from a crystallization performed to achieve the saturated fatty acids. These unsaturated free fatty acids were epoxidized with 30% H2O2 using immobilized Candida antarctica Lipase-B (CAL-B) as biocatalyst. The epoxy ring was cleaved with hot water in the presence of tert-butanol (t-BuOH). Pure threo-9, 10-dihydroxystearic acid (DHSA) from animal fat was recovered by crystallization (51% yield). Subsequently, DHSA was esterified in α-limonene using biocatalysts yielding twelve DHSEs (58–90% yield). Differential scanning calorimetry (DSC) analysis of these esters revealed potential latent heats ranging from 136.83kJkg−1 to 234.22kJkg−1 and melting temperatures from 52.45°C to 76.88°C. Finally, the compounds with enthalpies above 200kJkg−1 were subjected to 100 and 1000 thermal cycles. These experiments showed that these products present good thermal reliability.