• Title/Summary/Keyword: PMMA/silver microspheres

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Low Temperature Suspension Polymerization of Methyl Methacrylate for the Preparation of High Molecular Weight Poly(methyl methacrylate)/Silver Nanocomposite Microspheres

  • Yeum, Jeong-Hyun;Ghim, Han-Do;Deng, Yulin
    • Fibers and Polymers
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    • v.6 no.4
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    • pp.277-283
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    • 2005
  • In order to prepare high molecular weight poly(methyl methacrylate) (PMMA)/silver nanocomposite microspheres, methyl methacrylate was suspension-polymerized in the presence of silver nanoparticles at low temperature with 2,2'-azobis(2,4-dimethylvaleronitrile) as an initiator. The rate of conversion was increased by increasing the initiator concentration. When silver nanoparticles were added, the rate of polymerization decreased slightly. High monomer conversion (about $85\%$) was obtained in spite of low polymerization temperature of $30^{\circ}C$. Under controlled conditions, PMMA/silver microspheres with various number-average degrees of polymerization (6,000-37,000) were prepared. Morphology studies revealed that except for normal suspension microspheres with a smooth surface, a golf ball-like appearance of the microspheres was observed, due to the migration and aggregation of the hydrophilic silver nanoparticles at the sublayer beneath the microsphere's surface.

Effect of Modification of Silver Nanoparticles on the Preparation of Poly(methyl methacrylate)/Silver Microspheres via Suspension Polymerization (현탁중합에 의한 폴리(메틸 메타크릴레이트)/은 미세입자 제조에 은 나노입자의 개질이 미치는 영향)

  • Ji, Byung-Chul;Lee, Eun-Mi;Yeum, Jeong-Hyun
    • Polymer(Korea)
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    • v.34 no.4
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    • pp.341-345
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    • 2010
  • Effects of modification of silver nanoparticles on the polymerization rate and morphology of poly(methyl methacrylate)(PMMA)/silver microspheres prepared by suspension polymerization of MMA were investigated. The silver nanoparticles and their surface hydrophilicity played an important role in the polymerization rate and the morphology of poly(methyl methacrylate) (PMMA)/silver microspheres. The polymerization rate increased slightly with modified silver nanoparticles. PMMA/silver microspheres with conversion up to 85% were obtained in spite of the low polymerization temperature. Due to the change of hydrophilicity of silver nanoparticles, different appearances of the microspheres having golf ball-like convex surfaces or concave surfaces were observed. As the hydrophilicity of silver was decreased, stable nanocomposites were prepared.