Usually, m is 1; R1, R2, and R3 are alkyl groups and R4 and R5 are alkyl containing acyl groups and more commonly m=1; R1 and R3 are methyl or equivalent groups; R2 is an ethyl or equivalent group; and R4 and R5 are --CO(CH2)12 CH3 or equivalent groups or ##STR6## wherein: a, b, or d are the same or different and are from 0-10, usually between 0 and 3, preferably 0 or 1; R4 and R5 are the same or