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