Synthesis ester gum through esterification reaction of rosin and gliserol using zeolite modified by nickel as catalyst

Gum rosin is a solid component as a side product of the distillation process of pine resin or oleoresin. Based on data from Perhutani Indonesia, Indonesian gum rosin production in 2017 reached 80,000 tonnes (10% of world gum rosin production). Gum rosin is one of the commodities that have high market demand. Utilization of gum rosins, such as for additives in the synthetic rubber industry, paint industry, electronics, paper, and adhesive. The problem faced today is the high abietic acid content in rosin, causing increasing effects of crystallization and dark colors. So it is necessary to convert acid in gum rosin into ester form to maintain rosin stability from oxidation and reduce the effect of crystallization of gum rosin. The purpose of this study is to study the effect of reaction temperature (180-240 °C) and the ratio of catalyst (7-15% by weight) against conversion of gum ester. The synthesis process is carried on in a stirred batch reactor through an esterification reaction between gum rosin and glycerol using zeolite which modified by nickel metal as a catalyst. The reaction product was analyzed by FTIR and ASTM D-465 titration method to determine reaction conversion. From the experimental results obtained the highest conversion is reached in temperature reaction of 240 °C and catalyst ratio of 11 %