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OKUBO, Masayoshi; KATSUTA, Yoshiharu; Yamada, Akira; Matsumoto, Tsunetaka

doi:10.1295/koron.36.459

Cited by 27 publications

(10 citation statements)

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“…16 We believe that the copper ion absorbed by the latex particles might increase their surface charge and overcome the van der Waal forces between any nearby particles. A reaction using a redox initiation system with 1.0 ϫ 10 Ϫ3 mol/L K 2 S 2 O 8 , 1.0 ϫ 10 Ϫ3 mol/L NaSO 3 , and 3.5 ϫ 10 Ϫ3 mol/L CuSO 4 was conducted.…”

Section: Methods Used To Reduce the Particle Sizementioning

confidence: 96%

Poly(methyl methacrylate) nanoparticles prepared through microwave emulsion polymerization

Bao

Zhang

2004

J of Applied Polymer Sci

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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.

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Section: Methods Used To Reduce the Particle Sizementioning

confidence: 96%

Poly(methyl methacrylate) nanoparticles prepared through microwave emulsion polymerization

Bao

Zhang

2004

J of Applied Polymer Sci

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“…However, in a series of investigations on the production of composite polymer particles produced by seeded emulsion polymerization technique, we have found various anomalous particles [1][2][3][4][5][6]. Such anomalous shapes were based on heterogeneous structures formed in the early stage of the seeded emulsion polymerizations.…”

Section: Introductionmentioning

confidence: 94%

Morphology of anomalous polystyrene/ polybutyl acrylate composite particles produced by seeded emulsion polymerization

Okubo

Fujiwara

Yamaguchi

1998

Colloid & Polymer Science

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Recently, we found that ''golf ball''-like polystyrene (PS)/polybutyl acrylate (PBA) composite particles could be produced by seeded emulsion polymerization of butyl acrylate (BA) with PS seed particles. In this article, the effects of the polymerization temperature, BA monomer concentration, and the presence of 1-octanol, which is a good solvent for PBA and a poor solvent for PS in the polymerization, on the morphology was studied.

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“…These results indicate that polymer segments, including carboxyl groups, pulled up from the inside to the surface during the process of seeded emulsion polymerization, went back into the inside again by deionization and by an increase in mobility of the polymer segments in the particle. From the above and from the already accumulated results in our series of research on the morphologies of composite polymer particles [1][2][3][4][5]7], we propose that the production of anomalous P(S-BA-MAA)/P(S-BA) particles proceeds according to a schematic model shown in Figure 7. P(S-BA)-rich domains are predominantly formed at the surface layer of the ionized P(S-BA-MAA) seed particles in the initial step of the seeded emulsion polymerization, because the compatibility between the two polymers is low and the concentration of carboxyl groups is higher at the surface layer than inside the particles.…”

Section: Resultsmentioning

confidence: 74%

“…However, in a series of composite polymer particles, which respectively consist of two kinds of polymers, produced by seeded emulsion polymerization technique, surprisingly, we have found some anomalous polymer particles, e. g., "confetti-like" [1], "raspberry-like [2,3], "void" [4] and "snowman-like" [5] particles. Skjeltorp and coworkers [6] also found nonspherical polystyrene particles.…”

Section: Introductionmentioning

confidence: 80%

Production of anomalously shaped carboxylated polymer particles by seeded emulsion polymerization

Okubo

Kanaida

Matsumoto

1987

Colloid & Polymer Sci

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Anomalous polymer particles with a partial protuberance like "octopus ocellams" were produced under alkaline conditions by seeded emulsion copolymerization for styrene and butyl acrylate, with styrene-butyl acrylate-methacrylic acid terpolymer emulsion as seed. The mechanism of production of the polymer particles was studied. By transmission electron microscopic observation of the particles at each conversion, it was observed that the anomalous polymer particles were produced by partial growth of each of the individual seed particles throughout polymerization. Ionization of the carboxyl groups and low viscosity in the growing particles during the process of polymerization were important factors for partial growth.

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Cited by 27 publications

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Poly(methyl methacrylate) nanoparticles prepared through microwave emulsion polymerization

Poly(methyl methacrylate) nanoparticles prepared through microwave emulsion polymerization

Morphology of anomalous polystyrene/ polybutyl acrylate composite particles produced by seeded emulsion polymerization

Production of anomalously shaped carboxylated polymer particles by seeded emulsion polymerization

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