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