rbon atoms, p is a number of from 1-20, and Y represents a single bond or the group a is a number of from 1 to 100, X is a single bond or the group R1 and R2, independently of one another, are H or methyl, with the proviso that R1 and R2 are not both methyl at the same time, R3 is selected from H and branched and unbranched, saturated and unsaturated alkyl and acyl radicals having 1-30 carbon atom