The polymer 8, wherein at least 25% of the polymer comprises {HEAD ~ residues} of {TAIL ~ a compound} 1 
The polymer 8 , wherein at least 25 % of the polymer comprises { HEAD ~ residues } of { TAIL ~ a compound } 1
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH