The stability of the latex particles made with an emulsion polymerization process is dependent upon the balance between interparticle attractive van der Waals forces and repulsive electrostatic and steric forces. The electrostatic forces between particles arise from surface charged groups, which can be physically absorbed or covalent bonded to the particle surface. One way to manipulate the electrostatic force on a particle surface is through the incorporation of chargeable monomers, i.e. acid monomers.<br/>In this study, a series of butyl acrylate/methyl methylate based latex samples with different levels of acrylic acid were made using thermal or redox processes. The goal of the study was to develop a fundamental understanding of the incorporation of the acidic monomers. For the first time the new analytical technique of electrical flow-Asymmetrical Field Flow Fractionation (EIAFFFF) was applied to determine the variation in electrophoretic mobility across the particle size distribution. The results are compared to information obtained from alternative analytical techniques, such as Zeta-potential measurements using Phase analysis light scattering (PALS) and acoustic methods, serum phase polymer characterization by Liquid Chromatography with on-line Mass Spectrometry (LC-MS), bulk polymer characterization by (Gel Permeation Chromatography with online Multi-Angle Light Scattering detection (GPC-MALS), and acid distribution by titration. The study probed aspects of acid incorporation including: 1) how much acidic monomer is incorporated onto and into latex particles during emulsion polymerization; 2) how the incorporation of acidic functional group affects the aqueous phase and bulk polymers formed during emulsion polymerization process; and 3) how the particle surface charge being affected by the incorporation of acidic monomers.

Fundamental understanding of acidic monomer incorporation in acrylates emulsion polymerization

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.