0 to about 95% by weight of a structural unit represented by the formula ##STR5## wherein X2 is hydrogen, fluorine or methyl and {HEAD ~ X3} is C1 C10 alkyl group or {TAIL ~ C2 C10 fluoroalkyl group} ; and 
is
0 to about 95 % by weight of a structural unit represented by the formula # # STR5 # # wherein X2 is hydrogen , fluorine or methyl and { HEAD ~ X3 } is C1 C10 alkyl group or { TAIL ~ C2 C10 fluoroalkyl group } ; and
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH