Butyl Acrylate/Vinyl Acetate Miniemulsion Polymerization: A Study on Compartmentalization

Abstract

Summary: A series of butyl acrylate/vinyl acetate miniemulsions were investigated. Two procedures were used to prepare the miniemulsions: one in which the monomers were mixed together, sonicated, and polymerized, and the other, in which the individual monomers were sonicated prior to mixing and then polymerized. Kinetic and final properties of the obtained polymers were compared. The two procedures offer interesting insights into monomer compartmentalization in miniemulsions. In most cases, there were no differences in monomer conversion, copolymer composition, particle size or average molecular weights between the two procedures. ATR‐FTIR spectroscopy was used to assess possible monomer transfer. The spectra obtained from each polymerization procedure were compared and no evidence of compartmentalization was found. Both procedures yielded similar spectra indicating that monomer transfer between particles occurred. In addition, adhesive properties of the obtained latexes were investigated. Due to the fact that relatively large amounts of CTA were used, adhesive performance was poor.Comparison of the spectra of miniemulsion polymerizations obtained by two different procedures (BA/VAc 85/15 wt/wt).imageComparison of the spectra of miniemulsion polymerizations obtained by two different procedures (BA/VAc 85/15 wt/wt).

Glass‐transition temperature of a polyacrylate latex film and its water whitening resistance

“…Polyacrylate latex materials, though not new at all, have received keen interest recently in China due to the compulsive environmental regulations of the government, as well as their low cost, ease of handling, environmental safety, acceptable performance, and so forth . In the preparation of polyacrylate latex materials, however, water‐soluble initiators, surfactants, and monomers are usually employed, which cause the polymer latex film itself to be water sensitive.…”

“…Polyacrylate latex materials, though not new at all, have received keen interest recently in China due to the compulsive environmental regulations of the government, as well as their low cost, ease of handling, environmental safety, acceptable performance, and so forth. [1][2][3] In the preparation of polyacrylate latex materials, however, water-soluble initiators, surfactants, and monomers are usually employed, which cause the polymer latex film itself to be water sensitive. Such hydrophilic species, including nonpolymerizable surfactants, initiator residuals, or unreacted water-soluble monomers, may migrate toward the film-air or the film-substrate interface, or be strongly adsorbed by the latex particles during the film formation process.…”

On the Reaction Characteristics of Miniemulsion Polymerization with Aqueous Phase Initiation – Experiments and Modeling

“…In the latter case, an increase in particle number was observed, which was attributed to droplet budding, i.e., the splitting of nucleated particles throughout polymerization. Mixtures of separately prepared miniemulsion droplets, each consisting of only one monomer, showed a copolymer after polymerization rather than two separate homopolymers . Ugelstad et al derived a theoretical relationship between the particle diameter and the volumetric growth rate for seeded emulsion systems, thereby showing that concentration differences between differently sized particles can occur during polymerization, possibly resulting in monomer redistribution.…”