TAILIEUCHUNG - Kinetic study of synthesis reaction of lignosulfonate using isothermal differential scanning calorimetry method
The kinetics of lignin methylsulfonation in solution were studied by using differential scanning calorimetry (DSC) technique under an isothermal program, at 55, 65, 75 and 85 °C. It was found that the activation energy of the process was Eα = kJ/mol, and the preexponential factor A was ×103 s-1 . | Vietnam Journal of Science and Technology 55 (4) (2017) 443-451 DOI: KINETIC STUDY OF SYNTHESIS REACTION OF LIGNOSULFONATE USING ISOTHERMAL DIFFERENTIAL SCANNING CALORIMETRY METHOD Nguyen Truong Giang1, *, Tran Trung Kien2, Nguyen Thi Hoa2, Pham Van Thiem2 1 2 National University of Civil Engineering (NUCE), 55 Giai Phong, Hanoi School of Chemical Engineering, Hanoi University of Science and Technology (HUST), 1 Dai Co Viet, Hanoi * Email: truonggiangnuce@ Received: 18 December 2016; Accepted for publication: 28 February 2017 ABSTRACT The kinetics of lignin methylsulfonation in solution were studied by using differential scanning calorimetry (DSC) technique under an isothermal program, at 55, 65, 75 and 85 °C. It was found that the activation energy of the process was Eα = kJ/mol, and the preexponential factor A was ×103 s-1. Keywords: lignin, lignosulfonat, methylsulfonation, isothermal DSC. 1. INTRODUCTION Sulfonated lignins are polymers of phenylpropane with methoxyl groups that exhibit polyelectrolyte behavior in an aqueous solution and are very stable chemically. The properties of sulfonated lignins can vary depending on the molecular weights and molecular weight distribution, which is analogous to the distribution of the polymerization degree or chain length; the sulfonation degree; and the purity of the product [1]. Lignosulfonates are widely used in many fields of industry, . as dispersants in cement and kaolinite; as adsorbents on kaolinite and calcium carbonate to produce modified fillers for composites and papermaking, as flocculants for textile industry, etc. [2]. Synthesis of lignosulfonates by the two step process as presented in our previous study [3] showed many advantages such as high efficiency, smoothly reaction mode, shorter reaction time and lower reaction temperature. Several literature studies have been studied on the kinetics of lignin methylolation. In 1988, Gardner and Moginnis .
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