[0225] in which R??? denotes H or CH3, B denotes an ethyleneoxy radical, n is zero or denotes an integer ranging from 1 to 100, R denotes a hydrocarbon-based radical chosen from alkyl, arylalkyl, aryl, alkylaryl, and cycloalkyl radicals, comprising from 8 to 30 carbon atoms, such as from 10 to 24 carbon atoms and further such as from 12 to 18 carbon atoms.