Since the oxyalkylene groups as noted above, as well as the phenol group are reactive, the reaction with {TAIL ~ a certain amount} of isocyanate produces {HEAD ~ the desired urethane moieties thereon} 
Since the oxyalkylene groups as noted above , as well as the phenol group are reactive , the reaction with { TAIL ~ a certain amount } of isocyanate produces { HEAD ~ the desired urethane moieties thereon }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD