Another example is {HEAD ~ condensation polymers} having covalently bonded as {TAIL ~ repeating units} in the polymer chain, aromatic tetracarbonylbisimide groups of the formula II and III 
having covalently bonded as
Another example is { HEAD ~ condensation polymers } having covalently bonded as { TAIL ~ repeating units } in the polymer chain , aromatic tetracarbonylbisimide groups of the formula II and III
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH