Synthesis and rheological properties of carboxymethyl cellulose modified polyacrylic acid thickener with high electrolyte resistance

Herein, a method for preparing highly resistant electrolyte thickeners by introducing supramolecular interactions (multiple hydrogen bonds and electrostatic interactions) and chemical crosslinking during the polymerization of acrylic monomers has been proposed. The hydroxyl group on the carboxymethyl cellulose (CMC) unit provides multiple hydrogen bonds for the thickener structure, the carboxyl group on the polyacrylic acid (PAA) molecular chain provides electrostatic interactions for the thickener structure, and the crosslinking agent MBA forms a chemical network structure in the CMC-PAA molecular chain. The synergistic formation of multiple dynamic crosslinking points through the above effects is beneficial for improving the electrolyte resistance of CMC-PAA thickeners. The shift of the carbonyl characteristic peak on the FTIR spectrum confirms the existence of hydrogen bonding interactions between PAA and CMC. The viscosity retention rates of CMC-PAA thickener in tap water and saltwater electrolytes were 97.01% and 53.22%, respectively, exceeding our previously reported hydrophobic modified polyacrylic acid thickener, confirmed that the introduction of hydrogen bonds inhibits the contraction of molecular chains. The fitting analysis of the rheological properties of the color paste shows that the sisko model has high fitting accuracy of the color paste. In addition, CMC-PAA has excellent thermal stability and water-holding properties, which can ensure the contour clarity of subsequent inkjet printed fabrics. This study provides a new method for improving the electrolyte resistance of polyacrylic acid thickeners.