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