Molecular modeling studies of interactions between styrene–butadiene latex and sodium polyacrylate polymer surface

Abstract

The interaction between two important paper coating ingredients, sodium polyacrylate polymer dispersing agent and styrene–butadiene latex binder, was studied using classical force field and quantum chemical methods. The objective was to understand the adsorption of styrene–butadiene latex on the sodium polyacrylate polymer model surfaces at 300 K using molecular dynamics simulations. A quantum mechanical ab initio Hartree–Fock method was also used to obtain detailed information about the above interactions. In addition, the effect of moisture was investigated. Calculations showed that the conformation and orientation of styrene–butadiene latex, the number of carboxylate groups in the latex, and the characteristics of different sodium polyacrylate polymer surfaces affected the interplay between the styrene–butadiene latex and the surfaces. The force field applied and water molecules also had an effect on the adsorption process. Electrostatic interactions were observed to be important in the systems containing styrene–butadiene latex and the model surfaces. In addition, Hartree–Fock calculations suggested that the aromatic ring of styrene–butadiene latex was able to coordinate to the carboxylate group of sodium polyacrylate polymer via the sodium atom.