Effect of the chemical structure of carboxyl-containing polymers on precipitate morphology and carbonate dispersions stability

The influence of the molecular structure of carboxyl-containing polymers on their inhibitory and stabilizing effect in the precipitation processes was studied using a number of polymeric acids with different contents of carboxyl groups (X): polyacrylic acid (Mn = 5100 g-mol–1, X = 61.11 %), polymethacrylic acid (Mn = 5500 g-mol–1, X = 48.79 %), copolymer of methacrylic acid with turpentine terpene (α-pinene) (Mn = 350 g-mol–1, X = 14.54 %). It has been established that polyacid molecules slow down the process of crystal growth and recrystallization of the amorphous phase into more stable crystalline forms, which leads to a change in the morphology and structure of a carbonate precipitate. It has also been shown that polycarboxylic acids increase the colloidal stability of a mixed dispersion of carbonates and kaolin. The synergism of the stabilizing effect of mixtures of different hydrophobicity-polyacids was noted: in the presence of a mixture of polyacrylic acid with a copolymer of methacrylic acid with turpentine terpene, the stabilization effect increases 2 times compared to dispersion without additives and 1.4–1.8 times compared with individual components of the mixture.