Poly(methyl methacrylate) nanoparticles prepared through microwave emulsion polymerization

Abstract

ABSTRACT:The emulsifier-free emulsion polymerization of methyl methacrylate (MMA) was conducted with microwave irradiation. Superfine and monodisperse poly(methyl methacrylate) (PMMA) microspheres were obtained. Microwave irradiation notably promoted the polymerization reaction. This phenomenon was ascribed to the acceleration of the initiator [potassium persulfate (KPS)] decomposition by microwave irradiation. The experimental results revealed that the apparent activation energy of KPS decomposition decreased from 128.3 to 106.0 kJ/mol with microwave irradiation. The average particle size of the prepared PMMA latex was mainly controlled with the MMA concentration; it increased linearly from 103 to 215 nm when the MMA concentration increased from 0 to 0.3 mol/L and then remained almost constant at MMA concentrations of 0.3-1.0 mol/L. The KPS concentration had no effect on the average particle size, but the particle size dispersity was significantly reduced by a high KPS concentration. With a mixed polymerization phase (water/acetone ϭ 1:3 v/v) or a redox initiation system, PMMA nanoparticles were obtained with an average particle size of 45 or 67 nm, respectively.

Size controlled synthesis of sub-100 nm monodisperse poly(methylmethacrylate) nanoparticles using surfactant-free emulsion polymerization

“…One solution is to reduce the initial monomer concentration in SFEP, however, this typically yields very low solid content in the final dispersion [16,17]. To overcome this problem, microwave-assisted polymerization has been successfully utilized by various groups using acetone as the cosolvent [16,18,19]. Bao and Zhang used acetone-water solution in order to obtain sub-100 nm PMMA nanoparticles, however, the synthesized particles did not have monodisperse size distribution [18].…”

“…To overcome this problem, microwave-assisted polymerization has been successfully utilized by various groups using acetone as the cosolvent [16,18,19]. Bao and Zhang used acetone-water solution in order to obtain sub-100 nm PMMA nanoparticles, however, the synthesized particles did not have monodisperse size distribution [18]. An et al has reported the preparation of monodisperse PMMA nanoparticles at sub-100 nm scale.…”

Polysiloxane nanoparticles prepared by emulsion polymerization under microwave irradiation

“…It is no wonder that the different responses of two phases to MI may cause some unexpected results in the emulsion system. Most of the studies on microwave-assisted polymerizations have been focused on the latex particles prepared from styrene [6][7][8][9], methyl methacrylate [10][11][12][13], and butyl acrylate [14] etc. The study on the emulsion polymerization of PSi under MI, however, is still lacking.…”

Poly(methyl methacrylate) nanolatexes with high solid contents prepared by semi-continuous emulsion polymerization in the presence of oil-soluble initiators

“…The latex particles fabricated by the SEP method are usually in the range of submicrometer or larger [17][18][19]. Recently, several modified SEP techniques, which includes the use of an initiation accelerator composed of Cu(II)/EDTA complex, the use of acetone-water mixture as the reaction medium, and the combined use of acetone-water mixture and special heating methods (microwave irradiation or hydrothermal method), are developed to fabricate PMMA nanolatexes [20][21][22][23]. However, the monomer concentration is still limited (below 105 mg mL À1 ).…”