BASIC DESIGN OF PROCESS ENGINEERING FOR EPOXIDIZED NATURAL RUBBER PRODUCTION AS RAW MATERIAL FOR OIL RESISTANT PRODUCTS

Abstract

Natural rubber of Hevea brasiliensis is a natural polymer which has good damping properties and high elasticity. However, the natural rubber molecule is a nonpolar hydrocarbon polymer which easily swells in oil.  Epoxidizing the double bond of the natural rubber molecule is an effort to increase its polarity thereby increasing its resistance to oil. Several of its physical properties will also improve. Epoxidized natural rubber is made from the insitu epoxidation of the rubber molecule in the latex phase using performic acid made from hydrogen peroxide and formic acid. The aim of the experiments in this study was to design the process engineering of the epoxidation reaction from concentrated latex. The reaction was carried out at a temperature of 70 °C for 5 hours with the dose of hydrogen peroxide at 0.75 mol/mol isoprene unit and 0.4 mol/mol isoprene unit of the formic acid dose. The exothermic reaction occurred in a Batch Stirrer Tank Reactor (BSTR) which was equipped with a water cooling system to keep the reaction temperature constant. The reaction product was then neutralized with the addition of ammoniac and sodium thiosulphate in a neutralization tank. The product was then coagulated using a thermal extruder at 80-90 °C to produce Epoxidized Natural Rubber with 40% mol epoxy percent (ENR-40). The ENR was then washed with water to remove the acid residue. At the end, the ENR product was dried at 105 °C. The result showed that this basic design can be used as a reference to produce epoxidized natural rubber from the pilot scale to an industrial scale. Some parameters such as temperature, pressure, time conducted at each stage of the process, process flow diagram, process equipment, production efficiency, and the technoeconomy aspect need consideration in the design.

Keywords: batch stirrer tank reactor, concentrated latex, epoxidized natural rubber, oil resistance, process design