| To improve the strength of recycled pulp paper, the addition of paper strength agent in wet end of papermaking is an economic and easy way. In order to develop a new paper strength agent, at first, the terpolymer AM-ST-DADMAC was synthesized by soap-free emulsion copolymerization with acrylamide(AM), styrene(ST) and diallyldimethylammonium chloride(DADMAC). The effect of the total mass fraction of monomer and three kinds of monomer ratio on the total conversion rate, cationic monomer conversion rate and the solid content of terpolymer AM-ST-DADMAC were investigated using the gravimetric method and colloid titration, the solid content of the terpolymer AM-ST-DADMAC was up to 63%. The latex particle size and distribution were characterized by laser particle size analyzer and transmission electron microscopy (TEM). The results showed that the increase in the solid content gets latex with bigger particle size and wider particle size distribution was beneficial to improve the solid content, the latex with smaller particle size and narrower particle distribution was obtained with the decrease of mass fraction of hard monomer ST as well as the increase of the mass ration of the hydrophilic monomer AM, and the viscosity of the emulsion increase too. The effect of reaction conditions on the Hofmann reaction of the Soap-free Emulsion of terpolymer AM-ST-DADMAC was also investigated. The result indicate that an increase of NaOH dosage help to improve N-chloro amide (N-Cl) content and amination degree; N-Cl content increased with the decrease of the mass fraction of AM; when the AM mass fraction was 60%, the amination degree was up to 35.3%. Finally, the Soap-free Emulsion of terpolymer AM-ST-DADMAC and Hofmann modified products (CHPAM-ST-DADMAC) were applied in recycled pulp paper, the result shows that the CHPAM-ST-DADMAC is better for improving the paper strength than AM-ST-DADMAC, and the more content of N-Cl, the effect on to improve the paper strength is better. |
PDF Full Text Request