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Zhao Y.,Sichuan University | He J.,Jingkun Oil Field Chemical Company | Han X.,Sichuan University | Tian X.,Sichuan University | And 3 more authors.
Carbohydrate Polymers | Year: 2012

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 10 h at 25 °C. For the nucleophilic substitution of tosyl group with ethanolamine, the reaction was completed after 10 h 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. © 2012 Elsevier Ltd. All rights reserved.

Han X.-X.,University of Sichuan | Peng S.-H.,Jingkun Oil Field Chemical Company | Wu X.-Y.,University of Sichuan | He J.-P.,Jingkun Oil Field Chemical Company | And 3 more authors.
Gaodeng Xuexiao Huaxue Xuebao/Chemical Journal of Chinese Universities | Year: 2013

A novel N, O-carboxymethyl hydroxypropyl chitosan(HPCMS) derivative was prepared through two steps reaction. Water-soluble hydroxypropyl chitosan(HPCS) derivatives with degree of substitution of hydroxypropyl(DSHP) more than 0.8 were synthesized by reacting chitosan with propylene oxide(PO) using alkali as catalyst; then HPCMS with the DS of carboxymethyl(DSCM) ranging from 0.42 to 1.38 were prepared by reacting HPCS with chloroacetic acid under alkaline conditions. The structures of the polymers were characterized by FTIR and NMR. The results show that the alkylation mainly occur on the -OH groups at C6 in the reaction of chitosan with propylene oxide; and the -OH groups and -NH2 groups of HPCS are both alkylated in the reaction of HPCS with sodium chloroacetate.

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