Vinyl aromatic hydrocarbons reacted with glyceride oils using boron halide catalyst

Interpolymers are prepared from a vinyl aromatic hydrocarbon, e.g. styrene, with from 0.1 to 10 per cent thereof of a polyhydric alcohol ester of a drying oil fatty acid or a partially oxidized or partially polymerized derivative thereof, e.g. raw or blown linseed oil, stand oil and dehydrated castor oil, using as catalyst a boron halide, e.g. boron fluoride hydrate, if desired in the presence of a solvent, e.g. benzene. The styrene may be gradually added to the mixture of oil and catalyst. The catalyst is removed by blowing inert gas, e.g. carbon dioxide, through the reaction mixture at 140-240 DEG C. The products may be soluble in white spirit, raw or blown linseed oil, stand oil and oil-modified alkyd resins. They may be cooked with oleoresinous vehicles in known manner or incorporated with alkyd resins during their manufacture or added to the drying oil used to modify such resins.