Jojoba oil (Simmondsia chinensis) has been sulfur-brominated with sulfur monobromide in order to study the kinetics and parameters of the reaction and the mechanical properties of the product. Reaction runs were conducted in the range 1.1-8% S and 3.6-20.9% Br under different modes of operation. The reaction takes place by straight addition of the sulfur halide to the double bond. The decrease with time of the number of double bonds in solvents with different dielectric constant follows first-order kinetics. Mechanical testing of sulfur-brominated derivatives indicates that the product has superior properties as a lubrication additive, particularly for extreme pressure (Four-Ball weld point) load carrying applications.