Preparation and application of the cationic chitosan as dry strength agent

The synthesis of chitosan quaternary ammonium salt as dry strength agent was studied in this paper. Several dry strength agents were obtained by changing reaction conditions, such as reaction time, reaction temperature, the molar ratio of chitosan and the etherifying agent, and so on. Meanwhile, the application of these dry strength agents in papermaking of bleached bagasse pulp slurry was discussed. The dry strength of paper increased obviously. This kind of cationic chitosan was a good dry strength agent for bleached bagasse pulp. The mechanisms of cationic chitosan were discussed using the SEM (scanning electron microscope). The SEM image showed that the dry strength of additive significantly increased contact area between fibers.