Conversion of Technical Lignins to Amphiphilic Derivatives with High Surface Activity

To make use of technical lignins as a nonionic polymeric surfactant, we have already reported the modification of acetic acid lignin (AL) to amphiphilic derivatives by polyoxyethylation using two types of polyethylene glycol (PEG) with diglycidyl (PEGDE) and monoglycidyl (EPEG) groups.[ 1 Homma, H., Kubo, S., Yamada, T., Matsushita, Y. and Uraki, Y. 2008. Preparation and characterization of amphiphilic lignin derivatives as surfactants. J. Wood Chem. and Technol., 28(4): 270–282. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar] ] Kraft lignin (KL) was converted to amphiphiles in a similar manner. The resultant KL derivatives also indicated high surface activity. Polyethylene glycol with long alkyl chain was introduced to AL, KL, and lignosulfonate (LS) to prepare surfactants of high performance, using dodecyloxy-polyethylene glycol glycidyl ether (DAEO). The resultant DAEO-derivatives showed lower critical micelle concentration by 2–4 orders of magnitude than the corresponding PEGDE- and EPEG-derivatives. The DAEO-derivatives from LS showed better dispersibility for gypsum paste, one of cement components, than LS.