Carbohydrate polymers 2012-10-01

Modification of hydroxypropyl guar gum with ethanolamine.

Yongchao Zhao, Jianping He, Xiaoxiao Han, Xiulin Tian, Mingyu Deng, Weiping Chen, Bo Jiang

Index: Carbohydr. Polym. 90(2) , 988-92, (2012)

Full Text: HTML

Abstract

A new guar gum derivative containing amino group was synthesized through nucleophilic substitution of p-toluenesulfonate activated hydroxypropyl guar gum with ethanolamine. For the preparation of p-toluenesulfonate esters hydroxypropyl guar gum, the results showed that the reaction rate was optimal at 25 °C and the reaction could reach equilibrium state when it was carried out for 10h at 25 °C. For the nucleophilic substitution of tosyl group with ethanolamine, the reaction was completed after 10h reaction at 50 °C. The structures of products were characterized by NMR and FT-IR spectroscopy. The results showed that the p-toluenesulfonate esters can be effectively substituted by ethanolamine to form the hydroxyethyl amino hydroxypropyl guar gum (EAHPG). The content of nitrogen of EAHPG was determined by acid-base titration and element analysis.Copyright © 2012 Elsevier Ltd. All rights reserved.