Author(s): CHEN Mingqiang, LI Wenzuo, YANG Zhonglian, LIU Zuo, GAN Ziyu
Pages: 44-49
Year: 2015 Issue:  3
Journal: Journal of Anhui University of Science and Technology(Natural Science)
Keyword:  lignin; phenolation; epoxy resin; Epoxy Value ( EV);
Abstract: With ionic liquids as solvents , p-cresol as phenolic agent and concentrated sulfuric acid as catalyst , the alkali lignin (LG ) was modified by p -cresol.Then with NaOH as catalyst , lignin -based epoxy resin ( LGEP) was synthesized via the epoxidation reaction between the phenol lignin ( PLG)and 3-Chloro-1,2-epoxypropane (ECH).The structure of LG, PLG and LGEP were characterized by Fourier Transform -Infrared ( FT-IR) .The method of differential ultaviolet spectrophotometry was used to determine the phenoliehydroxyl group of PLG.The method of hydrochloric acid -isopropylalcohol was used to determine the Epoxy Value (EV) of LGEP.The orthogonal tests were designed to explore the optimal conditions for the phenolation of lignin and synthesis of LGEP process .The experimental results showed that the optimal conditions for the phenolation of lig-nin, which was 1.453 2mmol/g, were determined as follows:the dosage of p -cresol was 10 mLg/, and 60%sulfuric acid ,which was catalyst , was 10 mL/g, with the reaction temperature was 80℃and reaction time was 3 h.The optimal conditions for the synthesis of LGEP , which epoxy value was 0.431 , were determined as fol-lows:pH was 9, and molar ratio of phenolic hydroxyl group to ECH was 1∶2.5, with the reaction temperature was 90℃and the reaction time 5 h.