• Title/Summary/Keyword: photopoly-merization

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Syntheses and Optical Properties of Cholesteric Liquid Crystal Polymers Utilizing p-Phenylene Bis-(p-(3-acryloxy-2-methylpropyloxy)benzoate

  • Yoon, Ung-Chan;Choi, Jung-Hei;Jin, Sung-Ho;Song, Dong-Mi
    • Journal of Photoscience
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    • v.12 no.1
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    • pp.41-46
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    • 2005
  • We synthesized chiral choleseric liquid crystalline monomer p-phenylene bis-(p-3-acryloxy-2(S)-methylpropoxy)benzoate (1) and achiral nematic liquid crystalline monomer, p-phenylene p-acryloxy-6-hexyloxy-p-octyloxybenzoate (2) for the construction of cholesteric polymer network with a pitch gradient. In this research we attempted to synthesize cholesteric polymer film which have a wide reflection bandwidth in the region of visible wavelength with the synthesized chiral cholesteric monomer 1 and nematic monomer 2 under various photopoly merization conditions. We succeeded to construct cholesteric polymer film network with a pitch gradient covering more than 200 nm bandwidth in the visible wavelength by diffusion controlled photostructuring method.

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Synthesis and Antitumor Activity of Phthalimide-Based Polymers Containing Camptothecin

  • Lee, Neung-Ju
    • Macromolecular Research
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    • v.11 no.1
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    • pp.47-52
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    • 2003
  • The objective of this study was to develop a polymeric drug delivery system for camptothecin (CPT), capable of improving its therapeutic index and reducing its side effects. A monomeric conjugate, 3,6-endo-methylene-1,2,3,6-tetrahydrophthalimidoethanoylcamptothecin in (ETECPT) between CPT and 3,6-endo-methylene-1,2,3,6-tetrahydrophthalimidoethanoic acid was synthesized. Its homo-and copolymer with acrylic acid (AA) were prepared by photopolymerization using 2,2-dimethoxy-2-phenylacetophenone (DMP) as a photoinitiator. The monomer and its polymers were characterized by IR, $^1$H- and $^{13}$ C-NMR spectra. The ETECPT content in poly(ETECPT-co-AA) obtained by elemental analysis was 82 wt%. The number-average molecular weights of the polymers determined by gel permeation chromatography were as follows: M$_{n}$ = 11,400 for poly(ETECPT), M$_{n}$ = 17,900 for poly(ETECPT-co-AA). The $IC_{50}$/ values of ETECPT and its polymers against cancer cells were much larger than that of CPT. Our results from the in vivo antitumor activity indicated that all polymers show high antitumor activity than CPT at a dose of 100 mg/kg./kg.

Gas Permeation Properties of $CO_2$ Through Poly(ethylene Glycol) Diacrylate/Poly(Propylene Glycol) Diacrylate Membrane (Poly(ethylene glycol)diacrylate/poly(propylene glycol)diacrylate 막의 이산화탄소 기체 투과특성에 관한 연구)

  • Rhim Ji Won;Nam Sang Yong;Lee Sun Yong;Yun Tae Il
    • Membrane Journal
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    • v.14 no.3
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    • pp.250-257
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    • 2004
  • PEG(poly(ethylene glycol)) acrylate/PPG(poly(propylene glycol)) acrylate (PEG/PPG) was prepared using UV induced photopolymerization method to investigate gas permeation properties of the membrane. The effect of PPG content on the solubility, diffusivity, and permeability of $CO_2$, $O_2$, and $N_2$ in PEG/PPG membrane is reported at $25^{\circ}C$ and $35^{\circ}C$. PEG/PPG (9:1) membrane exhibits $CO_2$ permeability coefficient of 28.9 barrer and $CO_2$/$N_2$ pure gas selectivity of 57.9 at $25^{\circ}C$. Permeability coefficient of increased with increasing with PPG content in the membrane. PEG/PPG (5:5) membrane shows $CO_2$ permeability coefficient of 78.9 barrer and $CO_2$/$N_2$ pure gas selectivity of 33.2 at $25^{\circ}C$.