• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2008.10a
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• pp.11-12
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• 2008

Poly(ethylene oxide)(PEO) of molecular weight of 300,000 was crosslinked by UV irradiation in the presence of crosslinker. The photochemical crosslinking of PEO was enhanced by the addition of dimethacrylate crosslinkers in the film. Percent conversion of the polymer into gel as well as water absorbency were investigated gravimetrically. Gel fraction of PEO films increased with increasing crosslinker concentration. In the case of photocrosslinked PEO films with benzophenone, gel fraction reached about 95%. The thermal behavior of crosslinked PEO films was characterized by thermogravimetric analysis. The maximum decomposition temperature increased with increasing crosslinker concentration.

• Polymer(Korea)
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• v.32 no.3
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• pp.206-212
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• 2008

Alginate obtained from marine brown algae, is a copolymer with repeating units of $\alpha$-($1{\rightarrow}4$)-L-guluronic acid(G) and $\beta$-($1{\rightarrow}4$)-D-mannuronic acid(M). It has good properties such as biocompatibility, non-toxicity. and hydrophilicity. However, alginate alone cannot be electrospun due to high viscosity and conductivity. To solve this problem. electro spinning of sodium alginate(SA) was performed by blending with poly(ethylene oxide)(PEO) and poly(vinyl alcohol)(PVA) in this study. Characteristics of SA/PEO nanofibers and SA/PVA nanofibers were estimated by SEM and XRD analyses. Optimal nanofiber webs are obtained from 2/2 wt% of SA/PEO and 2/7 wt% of SA/PVA. SA/PEO and SA/PVA nanofiber webs may have potentials for tissue engineering scaffold and wound dressing.

• Macromolecular Research
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• v.11 no.5
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• pp.341-346
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• 2003

A poly(ethylene oxide)-b-poly(L-lactide) diblock copolymer (PEO-b-PLLA) is characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and a block length distribution map is constructed. Although the MALDI- TOF mass spectrum of PEO-b-PLLA is very complicated, most of the polymer species were identified by isolating the overlapped isotope patterns and by fitting the overlapped peaks to the Schulz-Zimm distribution function. Reconstructed MALDI-TOF MS spectrum was nearly identical to the measured spectrum and this method shows its potential to be developed as an easy and fast analysis method of low molecular weight block copolymers.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.183-183
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• 2006

Hyaluronic acid and chitosan-based poly(ethylene oxide) (HA-PEO and Chitosan-PEO) hydrogels have been employed as unique biomedical polymeric materials with properties such as bioactivity from polysaccharide, biocompatibility of HA and chitosan as well as PEO and control release of bioactive molecules from the hydrogel itself. We here examine in situ hydrogels based on hyaluronic acid and chitosan in terms of their synthesis, mechanical properties, morphologies and in vitro cellular interactions on their surface and inside. In vivo bone regeneration of HA-PEO and Chitosan-PEO hydrogels was compared with in mouse model.

• Macromolecular Research
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• v.10 no.1
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• pp.49-52
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• 2002

Rod-coil amphiphilic block copolymers, PALG-PEOs, poly(alkyl $\alpha$, L-glutamate-co-ethylene oxide)s, were successfully synthesized in three steps: 1) esterification of L-glutamic acid, 2) synthesis of ${\gamma}$-alkyl L-gultamate N-carboxyanhydride, and 3) polymerization of NCA monomers. These molecules form polymeric micelles with the hydrophobic core and hydrophilic corona in aqueous solution, which were characterized by light scattering and static fluorescence measurement.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.26 no.2
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• pp.93-98
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• 2020

The blends of Poly(lactic acid) (PLA) and Poly(butylene adipate-co-terephthalate) (PBAT) have been recognized as a replacement for commodity plastic films and bags in biodegradable packaging industries. The purpose of this study is to identify changes in the thermal and mechanical properties of PLA/PBAT blends with the addition of poly(ethylene oxide)(PEO). PLA (80%) and PBAT (20%) were melt mixed with 0 to 10 phr of PEO and processed using a hot press. The addition of PEO into PLA/PBAT increased the elongation at break and improved thermal stability. With PEO addition, two melting temperature (T_m) peaks of PLA/PBAT merged into one peak showing improved miscibility. The result of this study showed that the addition of PEO increased the ductility and thermal stability of PLA/PBAT blends.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.295-295
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• 2006

In present study, poly(acrylic acid) (PAA) and hydrophobically modified poly(ethylene oxide) (HM-PEO) multilayers based on the hydrogen bonding between the component polymer pair have been prepared by the LbL deposition method. Dip assembled HM-PEO/PAA multilayers yield unique film morphologies in comparison with PEO/PAA multilayers due to the micellar formation of HM-PEO owing to the hydrophobic attraction between alkyl chains end-capped with the PEO chains. Individual HM-PEO micelles were connected through the bridging PEO chains to form temporary networks on multilayer surface and induced peculiar surface morphology on HM-PEO/PAA multilayers above the critical number of bilayers.

• Macromolecular Research
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• v.17 no.12
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• pp.969-975
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• 2009

This article describes the topical delivery and localization of budesonide through the hairless mouse skin. Two poly(ethylene oxide)-block-poly($\varepsilon$-caprolactone)-block-poly(ethylene oxide) (PEO-PCL-PEO) triblock copolymers (T 222 and T 252) having different CL:EO ratios were added in the preparation of budesonide particles stabilized with poly(vinyl alcohol) (PVA) and Tween 80 under ultrasonication. For comparison, a commercial PEO-PPO-PEO triblock copolymer (F68) was studied under the same condition. To demonstrate the effects of the triblock copolymer, the particle size of budesonide emulsion, entrapment efficiency, and in vitro release were measured and compared. The budesonide particles stabilized by the triblock copolymers had a diameter of ca. 350 nm with entrapment efficiencies of 66-76%. The In vitro release profiles of all samples showed an initial burst followed by sustained release. The skin penetration and permeation of budesonide were analyzed by using a Frantz diffusion cell. T 222 and T 252 exhibited higher total permeation amounts, but lower budesonide penetration amounts, than F68. The results suggest that the partitioning of budesonide in each skin layer can be adjusted in order to avoid skin thinning and negative immune response arising from the penetration of budesonide in blood vessels.

• Polymer(Korea)
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• v.28 no.6
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• pp.455-459
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• 2004

Ionic conductivities of poly(ethylene oxide) (PEO)-based electrolytes are in a considerable inconsistency in many papers, varying more than three orders of magnitude for just same compositions. In PEO-salt-ceramic composite electrolytes, it has been also reported that the conductivity can be variant by almost three orders of magnitude according to thermal treatment and it has been regarded as a consequence of polymer-ceramic particle interaction. In this paper, we present a more systematic study on the change of ionic conductivity for ceramic-free PEO$_{10}$LiClO$_4$ polymer electrolytes, and found that the ionic conductivity can be variant more than hundred times according to thermal history. The slow recrystallization kinetics of PEO polymer is discussed to be responsible for the thermal history effect. Present results reveal that the effect of ceramic filler is not a main cause of the conductivity relaxation phenomenon.n.

• Membrane Journal
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• v.20 no.1
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• pp.13-20
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• 2010

Using poly(ethylene oxide) (PEO) as a polymer host, poly(ethylene glycol) (PEG) as a plasticizer, potassium iodide and iodine as sources of $I^-/{I_3}^-$ PEO-PEG-KI/$I_2$ polymer gel electrolytes were prepared. Based on the polymer gel electrolytes, solid-state dye-sensitized solar cell(DSSC)s were fabricated. The content of PEG in the electrolyte was changed from 0 to 85%. The electrolyte showed self-supporting form through whole range of the PEG content. As the PEG content increased, the ionic conductivity and ${I_3}^-$ diffusivity increased and the light-to electrical energy conversion efficiency increased under irradiation of 100 $mWcm^{-2}$ simulated sunlight.