More preferably, R1 is a linear or branched alkyl group having from about 8 to about 22 carbon atoms; R2 in each of the x (R2O) groups is independently ethylene or propylene; R3 is hydrogen, or a linear or branched alkyl group having from 1 to about 6 carbon atoms; R4 is a linear or branched alkylene having from 1 to about 6 carbon atoms, m and n are independently integers from 0 to about 7, the s