• Title/Summary/Keyword: In situ heating TEM

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Preparation of poly(methyl methacrylate)/clay nanocomposites by microwaveassisted in-situ radical polymerization

  • Jeong, Ji-Won;Kim, Dong-Hyun;Jang, Jae-Ho;Lee, Jung-Taek;Yoo, Kyung-Hyeon;Yoon, Seog-Young
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.29 no.1
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    • pp.19-23
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    • 2019
  • The PMMA (polymethyl methacrylate)/clay nanocomposites were synthesized by in situ radical polymerizations with different clay contents (3 and 7 wt%) using microwave heating. The nanostructure, optical, and thermal properties of the synthesized PMMA/clay nanocomposites were measured by XRD, TEM, AFM, UV-vis, and TGA. It was found that the intercalated- or exfoliated structure of PMMA/clay nanocomposites was strongly dependent on the content of clay. Thus, the imposition of microwave-assisted polymerization facilitated a delamination process of layered silicates to achieve exfoliation state of interlayer distance. The PMMA/3 wt% C10A nanocomposite with well-dispersed and exfoliated clay nano-layers showed the good optical transparency similar to pure PMMA in this study. The thermal decomposition rates of the PMMA/clay nanocomposites become to be lower compared to that of the pure PMMA, indicating the intercalated- or exfoliated inorganic silicate has high thermal stability. A possible reason is that the thermally segmental motion of PMMA polymer into inorganic silicate interlayer spacing has increased the thermal stability of the PMMA/clay nanocomposites.

Preparation of Silver/Polystyrene Nanocomposites by Radical Polymerization Using Silver Carbamate Complex (은 카바메이트 복합체를 이용한 라디칼 중합에 의한 은/폴리스티렌 나노복합체의 제조)

  • Park, Heon-Su;Park, Hyung-Seok;Gong, Myoung-Seon
    • Polymer(Korea)
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    • v.34 no.2
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    • pp.144-149
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    • 2010
  • Ag/polystyrene(PS) nanocomposites were prepared by in situ reduction of silver 2-ethylhexylcarbamate (Ag-CB) complex and follwing radical polymerization only by heating at 110 $^{\circ}C$. In contrast to this conventional heating method, the microwave irradiation afforded well-dispersed silver nanoparticles(NPs) in styrene monomer without polymerization. The synthesis of Ag NPs proceeded uniformly throughout the reaction vessel only under microwave irradiation, completing the reaction simultaneously in the whole reaction solution. Successive polymerization of the monomer containing the resultant NPs has successfully produced a hybrid of the silver NPs dispersed in PS matrix. Ag/PS (0.1/100) nanocomposites were prepared successfully by melt-mixing process using Ag/PS(4.0/100) as a master-batch. UV-VIS spectroscopy, TEM, and X-ray diffraction techniques were used to investigate the process of formation of Ag/PS nanocomposites.