Abstract NOVEL GLYCOL URETHANES HAVE THE GENERAL FORMULA: R1-NH-COO-(R2-O)N-R3 WHEREIN R1 IS AN ALKYL GROUP CONTAINING FROM 1 TO 4 CARBON ATOMS, AN ALLYL GROUP OR THE GROUP -R6-NH-COO-(R2-O)N-R7; R2 IS AN ALKYLENE RADICAL CONTAINING FROM 1 TO 4 CARBON ATOMS; R3 IS HYDROGEN, AN ALKYL RADICAL CONTAINING FROM 1 TO 4 CARBON ATOMS, OR ONE OF THE GROUPS R4-CO- OR R1-NH-CO-; R4 IS AN ALKYL RADICAL CONTAINING FROM 1 TO 4 CARBON ATOMS; R6 IS AN ALKYLENE GROUP CONTAINING FROM 1 TO 10 CARBON ATOMS; R7 IS AN ALKYL GROUP CONTAINING FROM 1 TO 4 CARBON ATOMS OR THE GROUP R4-CO-; AND EACH N IS THE SAME OR DIFFERENT AND IS AN INTEGER OF FROM 1 TO 6 AND WHEN N IS AN INTEGER GREATER THAN 1, EACH R2 MAY BE THE SAME OR DIFFERENT. A METHOD OR PREPARING THE NOVEL COMPOUNDS AND HYDRAULIC FLUIDS CONSISTING OF, OR COMPRISING THE NOVEL COMPOUNDS ARE ALSO DESCRIBED.