SYNTHESIS OF GLYCEROL CARBONATE AND KINETIC STUDY OF UREA GLYCEROLYSIS REACTION USING Zn(sec-BUTOXIDE) 2

• Main Author: Dwi Andriyani, Dita
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/42291
• Institution: Institut Teknologi Bandung

G vcero/ carbonate is one of value-added chemicu/.r; from glycerol. It has wzde applications, such as monomer for polycarbonate, surfactant , electrolytes, and alternative organic solvents. One of the promising route for glycerol carbonate :,ynthesis is urea glycerolysis. The route does not need solvent , and the co-product (NH3) may be cycledfor urea manufacture. The urea is also a readily available source. The reaction was initiated by catalyst to produce glycerol carbonate in a high yield and selectivity. Many researchs explore effective catalysts for such a reaction. One of the rarely explored caral_vst is Zn-alkoxy. The(irst Zn- alkoxy explored in the reaction was Zinc(monoglycerolate) (ZMG) . The reaction took place in 7 h and 5mol% catvast. The synthesis of ZMG was also a multi step reactwn. Therefore, exploration of a simple Zn(alkoxide) is interesting to be done. This research aims to study the .<.ynthesis of glycerol carbonate from Zn-cataly::ed urea glycerolysis. The Zn catalyst was prepared from the reaction between ZnCh and Al(OC.JH9h in dry THF Zn-alkoxide formation was observed from the Zn-0 alkoxy vibration at 902-910 em -1 Five parameters, i. e.. temperature, reaction time. catalyst concentration, and solvent were evaluated to seek an optimum reaction condition. The glycerol carbonate formatiOn was observedfrom the carbonyl cyclic vibration at 1780 -1790 cm-1 The optimum reaction was found at Zn-alkoxide concentration of 1 mol% at 150 "C, without solvent, glycerol and urea ratzo of 1:1 mole, for -1 hours. At such a condition, the yield and selectivity of glycerol carbonate were 77% and 95% respectively. The byproduct was 5-(hydroxymethyl) oxa::o/idin-2-one. The formation of this byproduct was indicated by a carbonyl cyclic vibration at 1725-1739 cm-1 The kinetic study indicated that the urea glycerolysis, cataly::ed by Zn(sec-butoxide)2 follows a pseudo first-order reaction with experimental activation energy of 38 kJ mol. The mechanistic stud! was observed from FTJR spectrum of cutaly::ed and uncatalv::ed reaction. The result shows that Zn(sec-butoxide)2 initiate the isocyanic cid production in urea glycero/_vsis reaction at early time reaction.