The alkyl alcohol is removed and {HEAD ~ the excess ethanolamine} is reacted with ethylene or propylene {TAIL ~ carbonate} to form the urethane diol 
The alkyl alcohol is removed and { HEAD ~ the excess ethanolamine } is reacted with ethylene or propylene { TAIL ~ carbonate } to form the urethane diol
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH