A novel associative latex thickener using ethoxylated behenyl methacrylate as functional monomer

Alkali-soluble associative latex thickeners modified with hydrophobic long chain alkyl groups were prepared using common acrylics and varying amount of a functional monomer, ethoxylated behenyl methacrylate (BEM), through emulsion polymerization. It was found that the size of the emulsion particle became larger with addition of BEM. The light transmittance of the thickener latex sharply increased with pH varied from 6 to 7. The associative latex thickener manifested a higher viscosity when solids in the latex thickeners were kept at 0.5 wt% or higher, and the optimal amount of BEM was found to be around 2.5 wt%, or 0.16 mol%. All thickener latexes modified with BEM have better shearing resistance than the BEM-free thickener.