Effect of epoxidized palm oil on physical properties of PVC plastics

Abstract

The research synthesized the epoxidized palm oil , a secondary plasticizer by in situ method through a 2(superscript 4) factorial design, for PVC compounding. The physical properties of the compounded PVC were studied in comparision to that containing the epoxidized soybean oil. Palm oil inclusive of the unsaturated fatty acids was epoxidized by 1.5 moles of 50% hydrogen peroxide; and 0.8 mole of glacial acetic acid for each mole of the double bond in palm oil; and concentrate sulfuric acid 2% by weight of palm oil. The reaction temperature was 50-55 oC; the agitation speed was 200 rpm; and the reaction time was 8 hours. The epoxidized palm oil possessed 3.17% of the oxirane oxygen. The epoxidized palm oil was compounded with PVC resin, bis-(2-ethyl hexyl) phthalate as a primary plasticizer and barium-cadmium-zinc stearate as a stabilizer. The physical properties were measured and compared with the PVC plastics compounded with the epoxidized soybean oil. The tensile strength and elongation were nearly equal but the hardness of the PVC compounded with the epoxidized palm oil was rather higher. These mechanical properties changed after the accelerated weathering test, tensile strength and elongation reduced but hardness increased. The thermal properties were studied for the efficiency of the epoxidized palm oil. The Tg and the decomposition temperature of both epoxidized oils were nearly equal. The major conclusion is that the epoxidized palm oil can function as a secondary plasticizer for PVC plastics like the epoxidized soybean oil.