Synthesis of chitosan composite microspheres and their application for the removal of stickies in the recycled paper

Abstract

Stickies deriving from the recycled paper had multiple deleterious effects on the paper chemicals, machine run-nability and paper equality. The aim of this study was to synthesize citosan composite microspheres and remove stickies in the recycled paper by microspheres. Citosan-montmorillonite and chitosan-ferroferric oxide composite microspheres were prepared by emulsion cross-linking method. The surface morphology of microparticels was analyzed by Digital microscope (DM) and Scanning electron microscope (SEM). The removal effects of composite microspheres and talc on stickies were compared. It was found that CS-MMT microspheres had excellent thermal stability than chitosan microspheres and CS-Fe3O4 microspheres. The zeta potential of stock increased with the addition of talc,CS-MMT or CS-Fe3O4. Comparing with the plate talc, CS-MMT or CS-Fe3O4 microspheres adsorbed more easily the stickies and removed DCS in the recycled paper. Meanwhile, CS-MMT or CS-Fe3O4 had less negative impact on the strength of paper than talc. It contributed that there was a large number of hydroxyl groups on the surface of composite microspheres. CS-Fe3O4 had magnetic characteristics and the ability of removing Dissolved and Colloidal Substances (DCS) in white water were superior to CS-MMT.