• Journal of the Korean Applied Science and Technology
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• v.21 no.4
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• pp.370-379
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• 2004

Highly crosslinked micron-size monodispersed PMMA/PDVB and PS/PDVB particles were prepared using seeded multi-stage emulsion polymerization. PMMA and PS seed particles were synthesized by seeded multi-stage emulsion polymerization and soap-free emulsion polymerization. Then PMMA/PDVB and PS/PDVB particles were obtained using semi-batch type emulsion polymerized using divinyl benzene as a cross-linkable monomer in the presence of seed particles. PMMA particles with size of ca. 730 nm and polydispersity of 1.03 were successfully prepared in this experiment. PS particles with size of ca. 1.5 ${\mu}m$ and polydispersity of 1.01 were prepared in this experiment. Highly crosslinked PS/PDVB particles with size of ca. 1.3 ${\mu}m$ and polydispersity of 1.00 were obtained.

• Applied Chemistry for Engineering
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• v.10 no.6
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• pp.889-894
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• 1999

Preparation of micron size polymer particles which have desired morphology, size, and structure by emulsion polymerization is very difficult due to coagulation of latex particles and formation of second generation particles. But there are attractive merits such as preparation of structural and functional polymer particles in seeded emulsion polymerization. Seeded emulsion polymerization of n-butyl acrylate(BA) was carried out to investigate the effects of stirring rate, reaction temperature, concentration of initiator, emulsifier, and cross-linking agent on the particle size and size distribution. By the combination of suitable reaction conditions, we succeeded in preparing $0.14{\sim}3.67{\mu}m$ diameter of poly(n-butyl acrylate)(PBA) particles using sequential seeded emulsion polymerization.

• Journal of the Korean Applied Science and Technology
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• v.19 no.2
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• pp.131-136
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• 2002

As model waterborne acrylic coatings, mono-dispersed poly(butyl acrylate-methyl methacrylate) copolymer latexes of random copolymer and core/shell type graft copolymer were prepared by seeded multi-staged emulsion polymerization with particle size of $180{\sim}200$ nm using semi-batch type process. Sodium lauryl sulfate and potassium persulfate were used as an emulsifier and an initiator, respectively. The effect of particle texture including core/shell phase ratio, glass transition temperature and crosslinking density, and film forming temperature on the film formation and final properties of film was investigated using SEM, AFM, and UV in this study. The film formation behavior of model latex was traced simultaneously by the weight loss measurement and by the change of tensile properties and UV transmittance during the entire course of film formation. It was found that the increased glass transition temperature and higher crosslinking degree of latex resulted in the delay of the onset of coalescence of particles by interdiffusion during film forming process. This can be explained qualitatively in terms of diffusion rate of polymer chains. However, the change of weight loss during film formation was insensitive to discern each film forming stages-I, II and III.

• Journal of the Korean Applied Science and Technology
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• v.21 no.1
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• pp.69-75
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• 2004

In this study, various model composite latexes were synthesized using n-butyl acrylate and methyl methacrylate as comonomers by seeded multi-staged emulsion polymerization. Monodispersed model composite latex particles with size of 190 nm and polydispersity index of 1.05, which have various morphology including random copolymer particle, soft-core/hard-shell particle, hard-core/soft shell particle, and gradient-type copolymer particle, homopolymers particles were prepared. The designed morphology of model composite particles were confirmed.

• Applied Chemistry for Engineering
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• v.17 no.2
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• pp.132-137
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• 2006

Polyurethane acrylate hybrid emulsions were prepared by seeded polymerization techniques. In the synthesis, seeded polyurethane dispersion containing a carboxylic group was used to endow hydrophilicity to the hybrid emulsion and various acrylates such as methyl methacrylate (MMA), 2-hydroxy ethylmethacrylate (2-HEMA), n-butyl acrylate (n-BA) and acrylic acid (AAc) were used to endow hydrophobicity. The particle size and distribution of various emulsion particles such as polyurethane acrylate hybrid emulsion, polyurethane dispersion homopolymer, acrylate emulsion, and physical blending emulsion were measured by a particle size analyzer. The average particle size of hybrid emulsion was greater than physical blending emulsion. And tensile strength, 100% modulus, elongation, and swelling properties of the polyurethane acrylate hybrid emulsion were studied and compared with those of polyurethane homopolymer, acrylate emulsion, and physically blended compositor, respectively. To improve chemical and physical resistance, this paper review a melamine hardener and compares it for effects on the physical properties of cured coating.

• Macromolecular Research
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• v.9 no.2
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• pp.122-128
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• 2001

Monodisperse composite latex particles with size of ca. 300 nm, which consist ofn-butyl acrylate as a soft phase and methyl methacrylate as a hard phase with different morphology, were synthesized by seeded multi-stage emulsion polymerization. Three types of composite latex particles including random-, core/shell-, and gradient-type particles were obtained by using different monomer feeding methods during semi-batch emulsion polymerization. Effect of poly(butyl acrylate)-poly(methyl methacrylate) rubber particle morphology on the mechanical and rheological properties of rubber toughened poly(methyl methacrylate) was investigated. Among three different rubber particles, the gradient-type rubber particle showed better toughening effect than others. No significant variation of rheological property of poly(methyl methacrylate)/rubber blends was observed for the different rubber particle morphology.

• Journal of Adhesion and Interface
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• v.13 no.3
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• pp.109-115
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• 2012

Monodisperse blue-colored poly(styrene-co-acrylic acid) latices were successfully prepared by seeded emulsion polymerization. Blue-colored latices with carboxyl anionic charge on the surface were synthesized at the second stage with the introduction of Blue 606 dye, acrylic acid, and 0.21 ${\mu}m$-polystyrene seed. All the blue-colored latices synthesized in this study were in the size range of 0.25~0.42 ${\mu}m$ and all uniform with less than 1.01 in PSD. The particle size increased with the addition of acrylic acid being delayed and colloidally stable latices were obtained over 30 min after its addition. The blue-colored latex with 20 wt% acrylic acid showed -145 mV of zeta-potential and $-9.4{\times}10^{-6}\;cm^2/Vs$ of electrophoretic mobility, and with 25 wt% of DVB showed high $T_g$ at 396.7 K.