Effect of cationic polyacrylamides on the interactions between cellulose fibers.
The interaction between cellulose fibers in the presence of cationic polyacrylamide (CPAM) was analyzed by rheology as a function of polyelectrolyte concentration, charge density, and molecular weight. CPAM was found to strongly influence the yield stress of cellulose suspensions; low doses of CPAM increased the yield stress, but at higher concentrations the yield stress declined. The charge density of the CPAM was the most significant factor in how yield stress responded to CPAM concentration; this effect was able to be normalized to a master curve by considering only the charged fraction of the polymer. The molecular weight of CPAM samples had some effect at high concentrations, but for lower CPAM doses the yield stress was independent of molecular weight over the range studied. The data suggest that CPAM modifies the interaction between cellulose surfaces via several mechanisms, with electrostatic interactions in the form of charge neutralization and charged patch formation dominating; polymer bridging and steric repulsion also influence the overall balance of forces between interacting cellulose fibers.
BioPRIA, Australian Pulp & Paper Institute, Department of Chemical Engineering, Monash University, Clayton, Victoria 3800, Australia. wade.mosse@monash.edu
Wade K J
WK
Mosse
David V
DV
Boger
George P
GP
Simon
Gil
G
Garnier
D000180:Acrylic Resins / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D002482:Cellulose / Q000737:chemistry*; D012212:Rheology; D055672:Static Electricity; D000099166:Polyacrylamides
D000180:Acrylic Resins; D002412:Cations; D002482:Cellulose; D000099166:Polyacrylamides