Effect of oil length of alkyd on the physico-chemical properties of its coatings

Abstract Alkyds of 50, 55, 60 and 66% oil length have been prepared using linseed oil, glycerine and phthalic anhydride, and pigmented with iron oxide at different PVC values. The adhesion of the coatings to a mild steel substrate together with the tensile strength, percentage elongation and toughness of the corresponding free films have been determined. The values of all the above properties were found to decrease with increasing oil length of the alkyd. The CPVC values of alkyd-iron oxide paints, determined from the data on adhesion and tensile measurements, were found to be closer and to increase with increasing oil length of the alkyd binder.