| The synthesis of cationic-modified poly (vinyl alcohol) by copolymerization of vinyl acetate (VAc) and diallyldimethyl ammonium chloride (DADMAC), followed by alkaline hydrolysis was systematically studied. The charge density and the structure of the resulting CPVA were characterized by polyelectrolyte titration and NMR. The parameters influencing the behavior of CPVA on the fiber surface were also investigated. As one of the potential applications, the flocculation of fine clay induced by CPVA was conducted. As another core research of this thesis work, cationic cellulose fibers were prepared by in-situ copolymerization using ceric ammonium nitrate (CAN) as a free radical initiator, followed by alkaline hydrolysis. The resulting cationic pulps led to significant improvement of filler retention and distribution.;In conjunction with anionic polymer carboxymethylcellulose (CMC), CPVA formed the polyelectrolyte complex which promoted the inter-fiber bonding significantly. Findings in this project provided important and useful information on newly developed cationic water soluble polymers. |
