• Title/Summary/Keyword: in situ free radical polymerization

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Effect of PTMGDA-PEGMA dopant on PVDF ultrafiltration membrane

  • Chen, Gui-E.;Huang, Hui-Hong;Xu, Zhen-Liang;Zhang, Ping-Yun;Wu, Wen-Zhi;Sun, Li;Liu, Yan-Jun
    • Membrane and Water Treatment
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    • v.7 no.6
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    • pp.539-553
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    • 2016
  • As a novel hydrophobic monomer, polytetrahydrofuran diacrylate (PTMGDA) was synthesized by the esterification reaction between polyethylene tetrahydrofuran (PTMG) and acryloyl chloride (AC). In situ free radical polymerization reaction method was utilized to fabricate poly (vinylidene fluoride) (PVDF)-PTMGDA-poly(ethylene oxide) dimethacrylate (PEGMA) ulrafiltration (UF) membranes. The performances of PVDF-PTMGDA-PEGMA UF membranes in terms of morphologies, mechanical properties, separation properties and hydrophilicities were investigated. The introduction of the PTMGDA-PEGMA dopants not only increased the membranes' pure water flux, but also improved their mechanical properties and the dynamic contact angles. The addition of the PTMGDA/PEGMA dopants led to the formation of the finger-like structure in the membrane bulk. With the increase concentration of PTMGDA/PEGMA dopants, the porosity and the mean effective pore size increased. Those performances were coincide with the physicochemical properties of the casting solutions.

Preparation and Characterization of Monolithic Poly(methacrylic acid - ethylene glycol dimethacrylate) Columns for High Performance Liquid Chromatography

  • Yan, Hong-yuan;Row, Kyung-Ho
    • Bulletin of the Korean Chemical Society
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    • v.27 no.1
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    • pp.71-76
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    • 2006
  • Porous polymer monolithic columns were prepared by the direct free radical copolymerization of methacrylic acid and ethylene glycol dimethacrylate within the confines of a chromatographic column in the presence of toluene-dodecanol as a porogenic solvent. The separation characteristics of the monolithic columns were tested by a homologous series of xanthine derivatives, theophylline and caffeine. The effects of the polymerization mixture composition and polymerization condition, mobile phase composition, flow rate and temperature on the retention times and separation efficiencies were investigated. The results showed that the selection of correct porogenic solvents and appropriate polymerization conditions are crucial for the preparation of the monolithic stationary phases. The separation efficiency was only extremely weakly dependent on flow rate and temperatures. Hydrogen-bonding interaction played an important role in the retention and separation. Compared with conventional particle columns, the monolithic column exhibited good stability, ease of regeneration, high separation efficiency and fast analysis.

Retention Mechanism of Caffeine and Tryptophan in Macroporous Poly[Methacrylic Acid-co-Ethylene Glycol Dimenthacrylate] Rods (매크로 다공성 Poly[Methacrylic Acid-co-Ethylene Glycol Dimenthacrylate] 막대에서 Caffeine과 Tryptophan의 체류 메카니즘)

  • Jin, Longmei;Yan, Hongyuan;Zheng, Jinzhu;Row, Kyung-Ho
    • KSBB Journal
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    • v.21 no.5
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    • pp.401-404
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    • 2006
  • Macroporous Poly(Methacrylic acid-co-Ethylene Glycol Dimethacrylate) Rods were in situ thermal initialized within a empty column($3.9{\times}150mm$) by free radical polymerization. The polymerization mixture was consisted of monomer, cross-linking monomer, porogenic solvent, initiator and control the ratio of these materials, column efficiency could be developed. Caffeine and tryptophan as separation substances and the retention mechanism of this kind of monolithic column was mainly hydrogen bond function.

Separation of Caffeine and Tryptophan Using Molded Macroporous Poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) Rods (주조된 매크로 다공성 Poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) 막대를 이용한 카페인과 트립토판의 분리)

  • Jin, Longmei;Yan, Hongyuan;Row, Kyung Ho
    • Korean Chemical Engineering Research
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    • v.43 no.5
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    • pp.603-608
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    • 2005
  • The molded macroporous poly (glycidyl methacrylate-co-ethylene glycol dimethacrylate) rods produced by a facile molding process were polymerized in situ within a tubular mold, chromatographic column ($4.6{\times}100mm$) by free radical polymerization. It was complemented by epoxy derivatized monolithic column and chemical modification of the epoxide groups with the sulphuric acid. By variation of the polymerization conditions, such as the ratio of the monomers, the porogen (pore generating material), and the temperature, the pore size could be varied, so the retention time of the samples may be adjusted. For the mixture of caffeine and tryptophan in the prepared monolithic column, the influences of polymerization material compositions to the efficiency, selectivity, and resolution of the monolithic column were investigated.