Solution properties of the acrylamide-modified cellulose polyelectrolytes in aqueous solutions.
A novel cellulose-based polyelectrolyte (AM-C) containing acylamino (DS=0.625) and carboxyl (DS=0.148) groups was homogeneously synthesized from cellulose with acrylamide in NaOH/urea aqueous solutions. Solution properties of AM-C in aqueous solutions were investigated by laser light scattering, rheometry, and viscometry. The results indicated that AM-C could form large aggregates spontaneously in water with or without the addition of salts by the strong hydrogen bonds and electrostatic interaction between acylamino and carboxyl groups. Steady-shear flow study showed a Newtonian behavior of the solutions in the dilute regime while a shear-thinning behavior as the concentration increases. The critical concentration (c(e)) for transition from dilute to concentrated solution was determined to be 0.7wt%. Aqueous solutions of AM-C displayed good thermo-stability, reversible liquid-like characters attributing to the chemical modification. The derivation from Cox-Merz rule at relatively low concentration was related to the co-existence of single chain and large aggregates of AM-C in dilute regime. As the polymer concentration increased, the AM-C system was transformed into a homogeneous entanglement structure, resulting in the disappearance of deviations from the Cox-Merz rule.
Song
Yongbo
Y
Department of Chemistry, Wuhan University, Wuhan 430072, China.
Zhou
Jinping
J
Li
Qian
Q
Lue
Ang
A
Zhang
Lina
L
D020106:Acrylamide / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry*; D004573:Electrolytes / Q000737:chemistry*; D009994:Osmolar Concentration; D012212:Rheology; D033081:Shear Strength; D012996:Solutions; D013696:Temperature; D014783:Viscosity; D014867:Water / Q000737:chemistry*
D004573:Electrolytes; D012996:Solutions; D014867:Water; D020106:Acrylamide; D002482:Cellulose