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