wherein R1 represents the remainder of a linear or branched higher fatty acid comprising from 7 to 19 carbon atoms, and R2 represents a branched hydrocarbon chain containing from 3 to 20 carbon atoms, such as for example the Purcellin oil (cetostearyl octanoate), isononyl isononanoate, C12-C15 alkyl benzoates;synthetic esters and ethers such as isopropyl myristate, ethyl-2-hexyl palmitate, octanoa