A novel macromer technique is described for the styrenation of triglyceride oils. Triglyceride oil-based macromers were prepared via successive transesterification ann condensation reactions. The macromers were styrenated at 100 degrees C using benzoyl peroxide as an initiator. The styrenation led to improved film properties with semidrying oils. Homopolymerization of the macromonomers failed due to the stearic hindrance of the bulky oil moieties. The results obtained were also evaluated by considering the degree of unsaturation.