Synthesis of Maleic Modified Rosin Ester from Pine Oleoresin

• Main Author: Kumalasari, Ihda
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/38628
• Institution: Institut Teknologi Bandung

Pine rosin is the main component in chemical products like paint and toners. Rosin comprises 80-90% of pine resin. Rosin is the result of pine resin vacuum distillation; the top product is turpentine while the bottom product is rosin. Rosin on its’s own is an unstable material, owing to the presence of double bond and hydroxyl group. These groups are prone to oxidation that may lead to quality degradation; mainly the color of the rosin. Severe oxidation caused by exposure to oxygen in the air or due to heating during distillation process results in the rosin turning a darker shade of color. On the other hand, carboxylic group is acidic and may cause corrosion to certain materials that are weak against acid. Few methods have been devised to counter this problem; one method is via maleic anhydride fortification. Rosin contains two types of acid, pimaric and abietic acid. Both acids contain double bonds and hydroxide groups. Maleic anhydride reacts with the double bond in the acid and stabilizes it by donating its electrons. This reaction is called Diels-Alder and it eliminates the double bond present in the acid, reducing the likeliness of oxygen reacting with rosin. Aside from the increased stability, maleic acid adducts are brighter in color and highly compatible with binding agent. This paper is meant to find the optimum method to synthesize maleic modiefied rosin ester, including its operating condition and stoichiometric ratio of the reactant. The product quality will be measured by its resistance to oxidation. Results from the experiment indicates that synthesizing maleic modified rosin ester requires the rosin to be esterified with glycerol for 6 hours at 250°C without vacuum; glycerol used is 1:3 mole ratio to rosin. Rosin ester is then reacted with maleic anhydride at 150°C to form maleic modified rosin ester. The reaction is done in vacuum for an hour with maleic anhydride in equal mole ratio to rosin ester. Clarity analysis of maleic modified rosin ester produced indicates that the product is strongly resistant to oxidation, showing a decrease in clarity by 0.5 %.