Copolymerization of an Unsaturated Oleic Acid Polyester Macromer and Methyl Methacrylate

Abstract

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][4][5][6][7][8][9][10][11][12][13][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][18][19][20][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.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.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 .Copolymerization was carried out in a glass reactor equipped with a condenser, mechanical stirrer, thermometer and dropping funnel. Initially the reactor was charged ...