• Macromolecular Research
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• v.12 no.4
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• pp.379-383
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• 2004

Poly(ethylene glycol)s (PEGs) are unique in their material properties, such as biocompatibility, non-toxicity, and water-solublizing ability, which are extremely useful for a variety of biomedical applications. In addition, a variety of functional PEGs with specific functionality at one or both chain ends have been synthesized for many specialized applications. Surface modifications using PEG have been demonstrated to decrease protein adsorption and platelet or cell adhesion on biomaterials. Furthermore, PEGs having anionic sulfonate terminal units have been proven to enhance the blood compatibility of materials, which has been demonstrated by the negative cilia concept. The preparation of telechelic PEGs having a sulfonic acid group at one end and a polymerizable methacryloyl group at the other is an interesting undertaking for providing macromers that can be used in various vinyl copolymerization and gel systems. In this paper, preliminary results on the synthesis and polymerization behavior of a novel PEG macromer is described with the aim of identifying a biocompatible material for applications in various blood-contacting devices.

• Journal of the Korean Chemical Society
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• v.57 no.3
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• pp.335-340
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• 2013

A chemical reaction of PBDEs was implemented using the polyethylene glycols (PEGs) and KOH, along with different reaction conditions such as temperatures and times. Removal efficiencies of PBDEs before and after chemical reaction were examined by difference of concentration. PBDEs was not removed at lower temperatures of 25 and $50^{\circ}C$. However, under the increased temperature, removal efficiency of PBDEs in ${\sigma}$-xylene was gradually increased, showing completely removal of PBDEs containing 5-6 bromines on biphenyl frame. When increasing the reaction conditions to 4 hours and $150^{\circ}C$, removal efficiency of PBDEs reached almost 100%. In studying the reaction of PEGs with PBDEs, it confirmed that the PBDEs led to less brominated by PEGs through a stepwise process with the successive elimination of bromines.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.1
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• pp.61-66
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• 2009

Characteristics of the photonic bandgaps (PEGs) in two-dimensional photonic crystals (2D PCs) with a square lattice have theoretically studied using a finite difference time domain (FDTD) simulation. In this paper, we propose a concept of optical coverage ratio (OCR) as a new structural parameter to determine the PEGs for E-polarized light. The OCR is an optically compensated filling factor. It is possible to normalize the PEGs of 2D PCs by introducing the OCR.

• Archives of Pharmacal Research
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• v.19 no.2
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• pp.100-105
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• 1996

Polyethylene glycols (PEGs; 400, 600, and 1000) were used to study the molecular weight (MW) permeability dependence in the rat ileal mucosa. Absorption of the PEGs was measured by following their recirculation perfusion over a 3 hr collection period. HPLC methods were used to separate and quantitate the individual oligomers present in the solution of PEGs mixtures (MW range 330 to 1 1 22 D). In the range studied, a distinct molecular weight cutoff was not identified. Corrected for the length of ileum used in the study, over the molecular weight range 330 to 1122 D, the apparent permeability $(P_{app)$ of PEG ranged from $3.2\pm0.06\times10_{-5} cm/sec(mean\pmSEM, n=7)\; to\; 0.1\pm0.02\times10^{-5} cm/sec.$ Also, it was observed that the apparent permeability was inversely proportional to approximately $MW^{2.4}$.

• Journal of the Korean Geotechnical Society
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• v.39 no.12
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• pp.23-35
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• 2023

The Ministry of Agriculture, Food and Rural Affairs has announced design standards for disaster-resilient greenhouses capable of resisting wind speeds with a 30-year frequency to respond to the destruction of greenhouses caused by strong winds. However, many greenhouses are still being maintained or newly installed as conventional standard facilities for the supply type. In these supply-type greenhouses, a small pile called a steel peg is used as reinforcement to resist wind-induced damage. The wind resistance of steel pegs varies depending on the soil environment and installation method. In this study, a correlation analysis was performed between the wind resistance of steel pegs installed in loam and sandy loam, using a soil hardness meter. To estimate the pull-out force of steel pegs based on soil water content and compaction, soil compaction tests and laboratory soil box and field tests were performed. The soil compaction degree was measured using a soil hardness meter that could easily confirm soil compaction. This was used to analyze the correlation between the soil compaction degree in the tests. In addition, a correlation analysis was performed between the pull-out force of steel pegs in the soil box and field. The findings of this study will be useful in predicting the pull-out force of steel pegs based on the method of steel peg installation and environmental changes.

• Applied Chemistry for Engineering
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• v.16 no.2
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• pp.206-211
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• 2005

Mediated electrochemical oxidation (MEO) of polyethylene glycols (PEGs) of molecular weight of 1000, 4000 and 20000, was carried out on both platinum (Pt) and titanium-iridium electrodes in 8.0 M nitric acid solution containing 0.5 M Fe(II) and Co(II) ion. The electrochemical parameters such as current densities, kinds of electrode, electrolyte concentration and removal efficiency were investigated in both Fe(III)/Fe(II) and Co(III)/Co(II) redox systems. The PEGs was decomposed into carbon dioxide by MEO in Fe(III)/Fe(II) and Co(III)/Co(II) redox system during 180 min and 210 min at the current density of $0.67A/cm^2$ on the Pt electrode. Removal efficiency of PEGs by MEO was better in Co(III)/Co(II) redox system than Fe(III)/Fe(II) redox system, indicating mediated electrochemical removal efficiency was 100%.

• Microbiology and Biotechnology Letters
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• v.22 no.3
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• pp.316-321
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• 1994

Several strains capable of degrading PEGs(Polyethylene Glycols) were isolated and investigated for their biodegradation ability of PEGs. Microorganisms screened for the biodegrada- tion studies were those grown on the PEG used as a sole carbon and energy source. It was known that the number of microorganisms decreased when grown on the high molecular weight of PEG. A biodegradation of PEG was investigated with such microorganisms in the reactor and resulted in the decrease in PEG concentration meaning that PEG was degraded in the reactor. This microorganism was identified as Flavobacterium sp. The biodegradability was found to be about 18.8% for PEG-8000 and 25.4% for PEG-10,000, respectively. For the manufacture of biodeg- radable PEG film, EMAA/PEG and EAA/PEG blending ability was investigated with IR spectrum and showed that it was possible to produce blending film.

• Journal of Nutrition and Health
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• v.29 no.2
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• pp.153-158
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• 1996

Polyethylene glycols(PEGs)are hydrophilic molecules that have been used to characterize intestinal permeability via the paracellular pathway. Using a mixture of PEGs(400, 600 and 1000), containing oligomers in the molecular weight range 330 to 1122 D, the molecular weight permeability dependence in the jejunum of the rat small intestine was examined, employing an in situ recirculation perfusion technique. Individual oligomers were determined by HPLC with refractive detection. In the range studied, a distinct molecular weight cut-off was not apparent. Corrected for the length of jejunum used in the study, over the molecular weight range 330 to 1122D, the apparent permeability(Papp) of PEG ranged from 4.92$\pm$0.02$\times$10-5cm/sec(mean$\pm$SEM, n=5) to 0.28$\times$10-5cm/sec. Also, it was observed that the apparent permeability was inversely proportional to approximately MW2. The results in this study suggest that molecular weight is an important factor in determining the intestinal permeability.

• Macromolecular Research
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• v.9 no.5
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• pp.253-258
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• 2001

Crosslinked poly(ethylene glycol)s (PEGs) were prepared by ultraviolet irradiation of low molar mass, liquid PEGs in the presence of benzophenone (BP) as a photoinitiator. The networks obtained have been characterized by DSC, IR, and contact angle measurements, and their water absorption and equilibrium swelling have been examined. The percent of gel formed and degree of swelling of the networks in water were dependent on the amount of BP in the reaction mixture, irradiation time and molar mass of PEG. Gel fraction yield exceeded 84%, and equilibrium swelling in water varied from 49 to 244%.

• Toxicological Research
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• v.31 no.2
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• pp.105-136
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• 2015

Polyethylene glycols (PEGs) are products of condensed ethylene oxide and water that can have various derivatives and functions. Since many PEG types are hydrophilic, they are favorably used as penetration enhancers, especially in topical dermatological preparations. PEGs, together with their typically nonionic derivatives, are broadly utilized in cosmetic products as surfactants, emulsifiers, cleansing agents, humectants, and skin conditioners. The compounds studied in this review include PEG/PPG-17/6 copolymer, PEG-20 glyceryl triisostearate, PEG-40 hydrogenated castor oil, and PEG-60 hydrogenated castor oil. Overall, much of the data available in this review are on PEGylated oils (PEG-40 and PEG-60 hydrogenated castor oils), which were recommended as safe for use in cosmetics up to 100% concentration. Currently, PEG-20 glyceryl triisostearate and PEGylated oils are considered safe for cosmetic use according to the results of relevant studies. Additionally, PEG/PPG-17/6 copolymer should be further studied to ensure its safety as a cosmetic ingredient.