The effects of acrylate monomers and polystyrene addition on the morphology of DOP‐plasticized styrene–acrylate polymer particles prepared by SPG emulsification and suspension polymerization

Abstract

ABSTRACT:Fairly uniform copolymer particles of methyl acrylate (MA), butyl acrylate (BA), or butyl methacrylate (BMA) were synthesized via Shirasu porous glass (SPG) membrane and followed by suspension polymerization. After a single-step SPG emulsification, the emulsion composed mainly of the monomers. Hydrophobic additives of dioctyl phthalate (DOP), polystyrene molecules, and an oil-soluble initiator, suspended in an aqueous phase containing poly-(vinyl alcohol) (PVA) stabilizer and sodium nitrite inhibitor (NaNO 2 ), were subsequently subjected to suspension polymerization. Two-phase copolymers with a soft phase and a hard phase were obtained. The composite particles of poly(St-co-MA)/PSt were prepared by varying the St/PSt ratios or the DOP amount. The addition of PSt induced a high viscosity at the dispersion phase. The molecular weight slightly increased with increasing St/PSt concentration. The multiple-phase separation of the St-rich phase and PMA domains, observed by transmission electron microscopy, was caused by composition drift because the MA reactivity ratio is greater than that of St. The addition of DOP revealed the greater compatibility between the hard-St and soft-MA moieties than that without DOP. The phase morphologies of poly(St-co-MA), poly(St-co-BMA), and their composites with PSt were revealed under the influence of DOP.

Manufacture of poly(methyl methacrylate) microspheres using membrane emulsification

“…It is clear that the particle size distribution matches closely the precursor oil monomer droplet characteristics in both cases. This is consistent with a number of earlier studies concerning the use of ME technologies for the preparation of precursor droplets in a suspension polymerization process [16][17][18][19][20]. The absence of agglomeration between droplets/particles during the polymerization process suggests that the added PVA is as effective as a steric stabilizer.…”

“…Despite this, stable dispersions of PMMA particles with diameters ranging from 3 to 35 µm were reported with a typical coefficient of variation (CV) of 10%. Later work from the same group describes a single-stage process for the emulsification of MMA prior to the subsequent polymerization reaction, although details of what had been modified to achieve this were not provided [18,19]. We assume here that the wettability of the membrane had been adjusted although this was not explicitly stated.…”

Synthesis by a single‐step swelling process and characterization of micrometer‐sized polychloromethylstyrene/poly(butyl methacrylate) hemispherical composite particles of narrow size distribution

“…[23][24][25][26] In contrast, particles with a hemispherical shape are usually produced by the swelling of the template PS particles with monomer(s) [e.g., butyl methacrylate (BMA)], which produce polymer(s) [e.g., poly(butyl methacrylate) (PBMA)] immiscible with the template PS particles. 28,[30][31][32][33] This article describes the synthesis and characterization of micrometer-sized polychloromethylstyrene (PCMS)/PBMA, composite particles of hemispherical morphology and narrow size distribution. These composite particles were prepared by a single-step swelling process of uniform PCMS template microspheres with emulsion droplets of BMA containing BP, followed by the polymerization of BMA at 738C within the swollen template particles.…”