Preparation of Aminated Lignin through Etherification and Amination

A new method for the preparation of aminated lignin (AEL) through etherification and amination reaction was presented. Chlorine atoms were firstly introduced into lignin through its etherification with epichlorohydrin. Then, hydrophilic amine groups were grafted to the modified lignin structure through amination with ethylenediamine to obtain AEL. Subsequent acidification of AEL led to the ionized aminated lignin (IAEL). The results of our analyses showed that the nitrogen content of AEL was 6.9%. Foaming and emulsifying experiments indicated that AEL had better foamability and emulsifying properties than IAEL. Surface tension tests showed that AEL and IAEL had similar critical micelle concentration (CMC). However, IAEL had lower surface tension (36.33 mN/m) than AEL (42.89 mN/m) at CMC. These results demonstrate the promising applicability of AEL as an emulsifier and that of IAEL as feedstock in the production of detergent and dispersant.