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