Supermicron polymer particles with core‐shell type morphologies

Cunningham, Michael F.; Mahabadi, H. K.; Wright, Heather

doi:10.1002/(sici)1099-0518(20000115)38:2<345::aid-pola9>3.0.co;2-#

Cited by 8 publications

(3 citation statements)

References 13 publications

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“…However, in the case of kinetically controlled two-stage emulsion polymerization, the conversion of the core also plays an important role to determine the internal morphology of the composite particles. Recently, Cunnungham et al 30 reported that the particle morphology could be controlled by varying the conversion of the core at which the second monomer addition began. In that study, when St was added in semicontinuous mode as the second monomer, particle morphologies were changed from core-shell to finely dispersed St domains in the PMMA core particles by varying the conversion inside the prepolymerized PMMA particles at the start of St feeding.…”

Section: Resultsmentioning

confidence: 99%

Preparation and Characterization of Core−Shell Particles Containing Perfluoroalkyl Acrylate in the Shell

et al. 2002

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We describe the preparation and characterization of core-shell latex particles, consisting of a polystyrene core, covered with a perfluoroalkyl acrylate shell. The core-shell particles were prepared by a two-stage emulsion polymerization under kinetically controlled conditions and were characterized by transmission electron microscopy, differential scanning calorimetry, and X-ray diffraction analysis. The surface properties of the latex films produced from the core-shell particles were investigated by the contact angle method. Compared with random copolymers or latex blends of styrene and perfluoroalkyl acrylate, the core-shell particles were the most effective to reduce the surface energy of the latex films. The effect of acetone as a cosolvent on the polymerization process was also considered.

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Section: Resultsmentioning

confidence: 99%

Preparation and Characterization of Core−Shell Particles Containing Perfluoroalkyl Acrylate in the Shell

et al. 2002

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“…It is known that a properly designed coating on a planar surface can significantly reduce the amount of light reflected over a range of visible wavelengths and angles 9. Synthetically, particles with defined layer morphology are possible by emulsion polymerization,10 suspension polymerization methods,11 or self‐assembly approaches 12, 13. We will therefore explore the possibility of producing antireflection coatings for small particles.…”

Section: Introductionmentioning

confidence: 99%

Scattering properties of core–shell particles in plastic matrices

Small

Hong

Pine

2005

J Polym Sci B Polym Phys

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Blending submicron rubber particles with plastics can enhance the mechanical strength of the composite material. However, the difference in refractive index between the particle and matrix scatters light, making the material more opaque. We consider the possibility of reducing a particle's scattering cross section by adding coatings. We find that adding coatings can reduce the amount of scattering by changing the effective dielectric contrast between the particle and the matrix. We also found that, when the refractive index of the particle is very close to that of the matrix the order of the layers can have significant effects on the transmitted light. Such effects may be useful for engineering the optical properties of particle-doped plastics. Resonant effects akin to those found in antireflection coatings on planar surfaces are difficult to obtain and rarely provide a significant reduction in scattering. We discuss theoretical models that can qualitatively explain some of our results.

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“…In addition, there have been several publication on the development of latex particle morphologies synthesized by seeded dispersion polymerization. Cunningham et al21 pointed out that the addition of a second monomer at low monomer conversions allows significant diffusion to occur within the particles, whereas delaying the addition of the second monomer until higher conversions leads to much slower internal diffusion rates. Control of the particle morphology is obtained by the manipulation of the monomer conversion at the beginning of the second stage of the reaction.…”

Section: Introductionmentioning

confidence: 99%

Effects of surfactants on the morphology of composite polymer particles produced by two‐stage seeded emulsion polymerization

Lee¹

2005

J. Polym. Sci. A Polym. Chem.

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Poly(methyl methacrylate) (PMMA)-polystyrene (PS) composite polymer particles were synthesized in the presence of a surfactant by two-stage seeded emulsion polymerization. The first stage was the synthesis of PMMA particles by soapless emulsion polymerization; the second stage was the synthesis of the PMMA-PS composite polymer particles with the PMMA particles as seeds. In the second stage of the reaction, three kinds of surfactants-sodium laurate sulfate (SLS), polyoxyethylene (POE) sorbitan monolaurate (Tween 20), and sorbitan monolaurate (Span 20)-were used to synthesize the PMMA-PS composite particles. Both the properties and concentrations of the surfactants influenced the morphology of the composite particles significantly. Core-shell composite particles, with PS as the shell and PMMA as the core, were synthesized in the presence of a low concentration of the hydrophilic surfactant SLS. This result was the same as that in the absence of the surfactant. However, a low concentration of Tween 20 led to composite particles with a core/strawberry-like shell morphology; the core region was a PS phase, and the strawberry-like shell was a PS phase dispersed in a PMMA phase. With an increase in the concentration of SLS, the morphology of the composite particles changed from core (PMMA)-shell (PS) to core (PS)-shell (PMMA). Moreover, the effects of a high concentration of Tween 20 or Span 20 on the morphology of the PMMA-PS composite particles were investigated in this study.

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Supermicron polymer particles with core‐shell type morphologies

Cited by 8 publications

References 13 publications

Preparation and Characterization of Core−Shell Particles Containing Perfluoroalkyl Acrylate in the Shell

Preparation and Characterization of Core−Shell Particles Containing Perfluoroalkyl Acrylate in the Shell

Scattering properties of core–shell particles in plastic matrices

Effects of surfactants on the morphology of composite polymer particles produced by two‐stage seeded emulsion polymerization

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