Effect of “hard” comonomers styrene and methyl methacrylate in ethyl acrylate/acrylic acid latices on their thickening with associative thickener

The rheological study of acrylate latices showed that an important factor influencing thickening with hydrophobically ethoxylated urethane (HEUR) associative thickeners is the effective hydrodynamic volume of latex particles, which in concentrated latices controls the remaining volume available for the thickener macromolecules. Thus, the larger volume corresponding to a smaller size of alkalinized swollen particles of ethyl acrylate/acrylic acid copolymers with “hard” comonomers methyl methacrylate or styrene leads to lower density of network structure of the thickener bridging the latex particles and, consequently, to lower viscoelasticity of the thickened material.