235 － 1 － 1．Introduction Depletion of petroleum resources and the rising cost of petroleum products have led to the increasing efforts to develop natural raw materials for industrial uses 1,2) . Vegetable oils have been important sources for the synthesis of green polyesters. There have been many studies on a wide variety of polymeric materials based on plant seeds and oils 3-14) . Acrylic monomers were first incorporated to improve the properties of the alkyd resins, predominantly for coating applications 15) . These polymers are synthesized by varying the type of acrylic or alkyd components and their ratio. The idea of a hybrid polymer is very attractive with the aims of combining the good properties of these two binders. Alkyd based coatings usually provide high gloss, good color retention, good heat and solvent resistance, low cost and an auto-oxidative crosslinking ability; however, their major weakness is the poor water, acid, and alkali resistance. On the other hand, acrylic resins are well-known to provide good water, acid, and alkali resistance and offer fast physical drying 15,16) . Combining these two chemistries may provide a combination of the positive characteristics in the new products 17-21) . The aim of this work was to use the palm oil derivatives as raw materials to produce an unsaturated macromer, which was then used for copolymerization with MMA. Evidence on formation of copolymer was provided by H-NMR and FTIR spectroscopy. Molecular weight and thermal analysis measurements were performed. To check the performance of these copolymers as coatings, drying times, pencil hardness, adhesion properties and chemical and water resistant behaviours were determined using standard test methods. 2．Materials and Methods 2.1 Materials Oleic acid (Purity 99.5%) and glycerol (purity > 99.5%) were obtained from Emery Oleochemicals Sdn. Bhd., Malaysia. Phthalic anhydride, PA, was from P.T. Petrowidada Indonesia. MMA monomer, benzoyl peroxide, toluene, ethanol, methanol, potassium hydroxide, and potassium hydrogen phthalate were reagent grade chemicals from Merck. Benzoyl peroxide, which was supplied with 25% moisture, was recrystallized from ethanol, followed by drying in a vacuum oven at 30˚C and kept in the fridge before use. 2.2 Synthesis of alkyd macromer Pre-weighed PA, oleic acid and glycerol were formulated according to the procedure of Patton 22) . The reactants were charged into a 2-L four-neck round bottomed glass reactor equipped with a condenser, thermometer, mechanical stirrer, and a Dean-Stark decanter for separating the water evolved from the reaction. The mixture was heated and stirred to 160- 180˚C for 1 h. The temperature was subsequently raised and maintained at 220-240˚C. The reaction was completed after the collected water of reaction was as predicted in the formulation. The alkyd macromer (AlkOA) was a viscous liquid at room temperature. Its properties are summarized in Table 1. 2.3 Synthesis of alkyd-methyl methacrylate (AM) copolymer Copolymerization was carried out in a glass reactor equipped with a condenser, mechanical stirrer, thermometer and dropping funnel. Initially the reactor was charged with known weight of AlkOA in 100 g toluene with the specified amount of MMA. Copolymerization of an Unsaturated Oleic Acid Polyester Macromer and Methyl Methacrylate Shahla ATAEI, Rosiyah YAHYA and Seng Neon GAN † Department of Chemistry, University of Malaya, Kuala Lumpur, 50603, Malaysia † Corresponding author, E-mail: sngan@um.edu.my (Received June 21, 2010; Accepted April 18, 2011) Abstract The oleic acid polyester macromer was synthesized from 40 parts of oleic acid, 34 parts of phthalic anhydride and 26 parts of glycerol. It might be copolymerized with MMA in toluene solution using a free radical initiator. The ratio between the macromer and MMA monomer was varied and the effect on the copolymers properties such as the glass transition temperature, molecular weight, thermal stability and film properties were studied. H-NMR spectroscopy was used to provide evidence of the reaction between the macromer and MMA during the copolymerization. Increasing the amount of macromer led to a decrease in the polymerization rate. On the other hand, increasing the amount of MMA leads to increasing molecular weight and higher Tg value. The coating obtained with the highest ratio of MMA exhibited the best overall physico-chemical properties. Results further reveal that the alkali and water resistance improved significantly with the increase in MMA content in the copolymer. Key-words: Oleic acid, Unsaturated alkyd macromer, Methyl methacrylate, Copolymerization, Coatings Original Research Paper J. Jpn. Soc. Colour Mater., 84〔7〕，235–241（2011）