A reaction product of isostearic acid (ISA) and tetraethylene pentamine (TEPA; Union Carbides HP TEPA) was prepared by adding 450 grams of isostearic acid to a 500 ml round bottom 4-neck flask equipped with a reflux condenser, a stirring bar and a nitrogen bubbler in order to obtain a level sufficient to permit agitation and heat transfer. The flask contents were then heated to 110° C. and 189 grams (about 1 mole) of TEPA were added slowly with mixing. After all of the TEPA was added to the flask, an additional 450 grams of ISA were added with stirring at 110° C. (a total of about 3.125 moles of ISA were added). The batch temperature was then raised slowly to drive the condensation reaction. Water of condensation began to appear immediately and was removed through the flask overhead system with a nitrogen sparge. After most of this water was removed (approximately 160° C.), vacuum stripping was applied and the flask temperature was raised to 200° C. to drive the condensation to completion. The reaction was complete after about 5 hours with 3 moles of isostearic acid (ISA) reacting with 1 mole of tetraethylene pentamine (TEPA) to form ISA-TEPA. The resulting product is designated friction modifier-1 (FM-1).
