THE PREPARATION AND APPLICATION OF AMPHOTERIC GELATIN USED AS PAPER DRY STRENGTH AGENT

摘要

A graft copolymer was synthesized by copolymerization of gelatin with methylacryloxyethyltrimethylammonium chloride (DMC), acrylamide (AM), acrylic acid (AA) and 2-acrylamido-2-methyl propane sulfonic acid (AMPS). The copolymerization was carried out in aqueous solutions using redox initiator, and its product was a kind of amphoteric graft copolymer. By testing the breaking length and burst index of handsheets, the optimum conditions of the amphoteric graft copolymer being used in bleached wheat pulp were obtained. When the dosage of the copolymer was 1.2%, pH value was 6, the reaction time was 4min, and the shearing rate was 300r/min, the breaking length and burst index of handsheets were increased by 17.82% and 26.94%, compared with the control sample. From the SEM pictures of handsheets, the mechanism of the effect of the amphoteric graft copolymer on handsheets was observed clearly.