Preparation of Cationic Chitosan-g-Polyacrylamide and its Performance on Strengthening Paper and Antibacterial Activities

A novel cationic polymer with long side chains (2,3-epoxypropyltrimethyl ammonium chloride (ETA) modified chitosan-graftpolyacrylamide, typically denoted as CTS-ETA-g-PAM) was prepared by grafting acrylamide onto the cationic modified chitosan. CTSETA-g-PAM samples were employed to modify the pulp fibers. The results indicated that: for the reaction of grafting polyacrylamide onto the cationic chitosan, the optimum initiator concentration, the degree of substitution (DS) of CTS-ETA (chitosan-2,3-epoxypropyltrimethyl ammonium chloride), reaction temperature and reaction time were 1.5 mmol/L, 0.369, 35 degrees C, 5 h, respectively. The CTS-ETA-g-PAM with higher percentage of grafting (PG) possessed more side chains, which could facilitate the formation of larger complexes among the CTS-ETA-g-PAM, microparticles and the fiber fines. The improved fiber wall strength would result in the improvement of the mechanical properties of the handsheets. As the percentage of grafting of CTS-ETA-g-PAM increased, no significant improvement was presented on antibacterial activities. However, the concentration of CTS-ETA-g-PAM had a strong influence on their antibacterial activities.