• 제목/요약/키워드: PEG

Search Result 1,403, Processing Time 0.129 seconds

The Vacuum Freeze-Drying Experiment for Water-logged Wood Excavated from Wolpyongdong in Taejon (수침목재(水浸木材)의 동결건조(東結乾燥) 실험보고 -대전(大田) 월평동출토(月平洞出土) 유물을 중심(中心)으로-)

  • Kim, Kyoung-su;Yi, Yong-hee
    • Conservation Science in Museum
    • /
    • v.1
    • /
    • pp.27-35
    • /
    • 1999
  • To get the best result from vacuum freeze drying of water-logged wood, it is necessary for objects to find out the best conditions such as chemicals, appropriate concentration of solution, impregnation method and etc. Such best conditions could be set up by pre-treatment experiments. Two kinds of wood(Pinus densiflora S. et Z. and Quercus acutissima Carruth) were pre-treated by four methods: 2-step PEG treatment(PEG#200-PEG#4000), sorbitol treatment, PEG#200+PEG#4000 treatment, and sorbitol+PEG#4000 treatment. After those pre-treatment, vacuum freeze-drying was undertaken. Then the effect of dimensional stability were compared. When using 2-step PEG treatment, a solution of 60% PEG #4000 got the best dimensional stability for pine and in case of the oak, a solution of 40% PEG#4000 got the best. Sorbitol treatment got rather good result for the pine only when applied with 40% solution of sorbitol. Sorbitol, PEG#200+PEG#4000 and sorbitol+PEG#4000 treatments to the oak didn't affect on dimensional stability sufficiently.

A Study on the Dimensional Stability of Archaeological Waterlogged Salix koreensis Andersson Treated with Recycled PEG (재활용 PEG를 이용한 수침 고버드나무의 치수안정화 연구)

  • Yang, Seok-Jin;Lee, Soo;Kim, Jong-Hwa
    • Journal of the Korean Applied Science and Technology
    • /
    • v.31 no.4
    • /
    • pp.635-641
    • /
    • 2014
  • Archaeological waterlogged woods require a process of dimensional stabilization for their conservation. PEG is the most widely used in the conservation of archaeological waterlogged wood. One of the easiest and commonly used methods is the impregnation of 40% polyethylene glycol followed by vacuum freeze drying. However, the waste fluid produced from the PEG treatment is black in color and has a severe odor due to the organic matter extracted from the wood. Thus It cannot be recycled and it was just thrown out. Color of waste fluid can be decolored with oxidation reaction by hydrogen peroxide. Properties of PEG before and after preservation treatment, and after oxidation with $H_2O_2$ were not changed. Dimensional stability of archaeological waterlogged Salix koreensis Andersson was studied with pure or recycled PEG. The ratio of impregnation solutions were 10:0, 7:3, 5:5, 3:7, 0:10 (pure PEG : recycled PEG). Impregnation process was carried out by putting the wood specimens 10% PEG solution for 5days, 20% for 5 days, 30% for 5 days finally 40% for 5 days. All of the specimens showed the weight change rate of 25%. SEM results provided that the dimensional change of were less than 4% PEG impregnated specimens. Comparing with pure PEG impregnation system, conservation precess mixed PEG also showed no significant changes. Conclusively, the recycled PEG can be used for archeological waterlogged wood conservation precess.

Germination Characteristics of PEG Priming Seed in Barley (Hordeum vulgare L.) (PEG로 프라이밍 된 보리(Hordeum vulgare L.)종자의 발아특성)

  • 이성춘;박문수;배창휴
    • Korean Journal of Plant Resources
    • /
    • v.15 no.1
    • /
    • pp.18-25
    • /
    • 2002
  • These experiments were conducted to evaluate the variability of seed germination, and seedling growth of PEG priming barley. The average germination percentage(AGP) of PEG priming seed was higher than control, but those were low with extend the treatment period. The AGP of washing seed after PEG priming was higher than unwashed seed, and that of redried seed after priming was lower than control. The germination time of priming seed was short compare to control seed, and that was prolonged with extend the priming period, and that of washing seed after priming was shortening, and that of redried seed after priming was prolonging. The emergence percentage(EP) of priming seed was higher than control, and the emergence time was shortest in 50% field moisture capacity soil. The seedling and root length of priming seed was shorter than control.

Synthesis and Blood Compatibility of New Biocompatible Copolypeptides : Blood Compatibility of Copolypeptide Having Ethylene Glycol Oligomers Substituted in the Side Chain (새로운 생체적합성 폴리펩티드공중합체의 합성과 혈액적합성에 관한 연구 : 측쇄에 에틸렌글리콜을 함유하는 폴리펩티드 공중합체의 혈액적합성)

  • Inn-Kyu Kang;Sang Dong Park;Chong Su Cho;Yong Kiel Sung
    • Journal of the Korean Chemical Society
    • /
    • v.36 no.6
    • /
    • pp.947-954
    • /
    • 1992
  • Polyethylene glycol (PEG) grafted poly (γ-benzyl L-glutamate) (PBLG) was synthesized by the substitution reaction of PBLG and PEG having primary amino groups at both ends. PEG-g-PBLG films containing hydroxyl group were also prepared by the substitution reaction of PEG-g-PBLG film and ethanolamine (EA). Adhesion of platelets and activation of plasma proteins on the copolypeptide films were studied. The results showed that platelets are less adhered and activated on the PEG-g-PBLG than on other polypeptides and plasma recalcification time (PRT) on the PEG-g-PBLG was longer than that on other polypeptides. These results were consistent with those of blood clotting time and thrombus formation on the polypeptides. As a results, PEG-g-PBLG surfaces showed better blood compatibility than PBLG or PEG-g-PBLG-EA surfaces.

  • PDF

Penetration of PEG by Treatment Condition of Waterlogged Wood (수침고목재의 처리조건에 따른 PEG 침투상태)

  • Lee, Gyeong-Cheol;Lee, Jong-Shin
    • Journal of Conservation Science
    • /
    • v.29 no.3
    • /
    • pp.243-247
    • /
    • 2013
  • This study was conducted to investigate the penetration of PEG for conservation treatment conditions of archaeological waterlogged wood. The weight percent gain was examined, depending on the solvent of PEG, concentration and treatment period and temperature of treatment solutions. The penetration of PEG in the cell lumina of treatment woods was observed by scanning electron microscope. The results showed that the type of solvents had no influence on PEG penetration. In the concentration of the PEG treatment solutions, the weight percent gains (WPGs) were increased with increase in concentration of PEG. In terms of the period of the soaking treatment, a maximum WPGs were obtained for only 20 days. There was no distinctive difference in the WPGs by difference the temperature of the treatment. In conclusion, in the conservation of small size of archaeological waterlogged wood, it is confirmed that optimal solvent type and treatment period of PEG are water and 20 days, respectively.

Effects of PEG Treatment on Seed Viability and Seedling Emergence in Rice, Barley and Wheat (벼, 보리, 밀 종자의 PEG 처리가 종자활력과 포장출아에 미치는 영향)

  • 이성춘;김진희;정춘화
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.41 no.2
    • /
    • pp.145-156
    • /
    • 1996
  • The effects of priming with different polyethylene glycol (PEG 6, 000) solutions on the germination, emergence characteristics and early plant growth in rice, barley and wheat were investigated. Rice, barley and wheat seeds were subjected to various priming conditions of osmotic potentials (-0. 75, -1.00 and -1.50 MPa) of PEG, and incubation period were 5 days at 25, 20, 2$0^{\circ}C$, respectively. The percentage of water absorption was highest in barely, and lowest in rice, and all the treatments enhanced water absorption in barley, but showed no significant effects in rice and wheat. Respiration quotient was lower than none PEG treatment seeds, and those of barley and wheat were higher than rice regardless of PEG concentration, and that of rice increased with high PEG concentration. Total germination percentage of osmoconditioning seeds with PEG was higher than that of none treatment seed, and those of barley and wheat were significant. The artificially deteriorated seeds with PEG treatment seeds after ageing treatment could recover to nearly the same germination level as that of the control seeds. The effects of coating polymer were higher than osmoconditioning with PEG, and germination characteristics in rice showed varietal difference at PVP and waterlock at recoated seeds after PEG treatment. Osmoconditioning with PEG reduced mean germination and emergence time, but there was no difference among PEG concentrations. The plant height of PEG treaed seed in rice was taller and those of barely and wheat showed varietal difference, and those of polymer-coated seed after PEG treatment were different among the polymers. The dry weight of PEG treatment were different among the crops, and those were increased with the high PEG concentration. The emergence percentage of PEG-treated seed were higher than none-treated seed, and those were decreased with the increased PEG concentration, and the highest emergence percentage of rice, barley and wheat were 90, 50 and 50% soil moisture content, respectively. The time to emergence in rice was longer than barley and wheat, and those in rice was shortened in high soil moisture content, and barley and wheat were shortened in low soil moisture content.

  • PDF

Process Development for Alcohol Production by Extractive Fermentation (추출 발효에 의한 알콜 제조 공정개발 -PEG/Dx 최적 이상계의 선정-)

  • 김진한;허병기목영일
    • KSBB Journal
    • /
    • v.6 no.2
    • /
    • pp.175-180
    • /
    • 1991
  • The quantitative effects of molecular weight and concentrations of two phase-forming polymers-polyethylene glycol and crude dextran on the two phase extractive ethanol fermentation were investigated using a Box-Wilson central composite protocol. The regression model obtained was used in order to determine optimum compositions of aqueous two phase system. In the aqueous two phase extractive ethanol fermentation of Kluyueromyces fragilis CBS 1555 with Jerusalem artichoke juice, it was found from the regression model that the variables influenlcing on ethanol fermentation were PEG concentration, time, Dx concentration, and PEG molecular weight strongly in order. The interaction of PEG concentration and PEG molecular weight was also found, and the effect of PEG concentration decreased with increase in molecular weight of PEG. The ethanol concentration incresed with increase in molecular weight of PEG, and with decrease in concentration of PEG. In conolusion, maximum concentration of ethanol produced was obtained at the following compositions; PEG MW 20000, Dx concentration ranged from 4% to 5%, and PEG concentration ranged from 3% to 7%.

  • PDF

Humidity-Controlled Drying of PEG-Treated Waterlogged Woods (PEG처리 수침고목재의 조습건조)

  • Lee, Kwang-Hee;Kim, Soo-Chul;Park, Won-Kyu
    • Journal of Conservation Science
    • /
    • v.27 no.1
    • /
    • pp.91-100
    • /
    • 2011
  • This study is to examine the PEG concentration, and drying humidity and drying periods of humidity-controlled drying(HCD) for conservation of waterlogged woods(Pinus densiflora S. et Z.), and dimension stability of HCD were compared with those of air-drying and vacuum freeze-drying(VFD). Dimension stability of vacuum freeze-drying was the most excellent, i.e., PEG crystal was uniformly distributed in woods. Increasing concentrations of PEG, dimension stability of HCD was increased and drying periods decreased. Dimension stability of HCD after the treatment with the high concentration(70%) of PEG soaking was similar to those of VFD after the treatment with the low concentration(40%) of PEG soaking. In conclusion, high concentration(about 70% in water) PEG solution was the most suitable as a pre-treatment for HCD of waterlogged woods. However, drying should be maintained with enough high humidity and longer period.

A Study onthe Durable Hydrophilic Finish of Synthetic Fiber (III)-Synthesis of Bisulfite Adduct of PEG- HMDI Prepolymer and Its Application to PET Fabric- (합성섬유의 내구성 친수화 가공에 관한 연구(III) -PEG- HMDI Prepolymer의 Bisulfite Adduct의 합성과 PET 직물에의 적용-)

  • 김갑진;이영호
    • Textile Science and Engineering
    • /
    • v.28 no.8
    • /
    • pp.26-34
    • /
    • 1991
  • This study is related to the hydrophilic finishing of PET fabric with bisulfite adduct of NCO-terminated polyethylene glycol (PEG) -hexamethylene diisocyanate (HMDI) prepolymer. Through the reaction with excess sodium bisulfite of NCO-terminated PEG-HMDI prepolymer (NCO-t-PEG) derived from HMDI and PEG, the bisulfite adduct of NCO-t-PEG(PEG- PCS), which is water-soluble, could be obtained. The thermal property of hexamethylene disodium carbamoyl sulfonate(HMDSCS) as a model compound of PEG - PCS was investigated with DSC. It was dissociated to HMDI and sodium bisulfite near at 187$^{\circ}C$ under the nitrogen atmosphere. Therefore the dissociation temperature of PEG- PCS to NCO-t-PEG and sodium bisulfite might be sulfester to be the same as that of HMDSCS. This dissociation temperature, however, was too high to adopt as curing temperature for the hydrophilic finishing of PET fabric. HMDSCS and PEG- PSC were stable in acidic solution, but dissociated to free NCO group anti Sodium bisulfite in alkalise Solution. 50 the mixture Of Na2C03/NaHC03 W3S USfd 353 latent alkaline catalyst. PET fabric was padded with the aqueous solution containing PEG- PCS, crosslinking agent such as polyethyleneimine, and the latent alkaline catalyst, dried at 100$^{\circ}C$ for 3min, and cured at 140$^{\circ}C$ for 1 min. This finished PET fabric showed very low frictional electrostatic charge, short half-decaying time, soft handle, and good wicking properties. And these properties were durable to the repeated launderings.

Topology effects on the LCST of end-capped poly(ethylene glycol)s

  • Kim, Jin Young;Moon, Hyo Jung;Ko, Du Young;Jeong, Byeongmoon
    • Biomaterials and Biomechanics in Bioengineering
    • /
    • v.2 no.1
    • /
    • pp.15-22
    • /
    • 2015
  • Poly(ethylene glycol) end-capped with pentafluorophenyl group(s) in ABA (FP-PEG-FP) and AB (mPEG-FP) types were prepared. Even though they were similar in composition, the lower critical solution temperature (LCST) of FP-PEG-FP was observed at $23^{\circ}C$, whereas that of mPEG-FP was observed at $65^{\circ}C$. To understand the large difference in solution behaviour of the two polymers, UV-VIS spectroscopy, microcalorimetry, 1H-NMR spectroscopy, and dynamic light scattering were used. FP-PEG-FP has two hydrophobic pentafluorophenyl groups at the ends of hydrophilic PEG (1000 Daltons), whereas mPEG-PF has a highly dynamic PEG (550 Daltons) block that are anchored to a hydrophobic pentafluorophenyl group. PF-PEG-PF not only has a smaller conformational degree of freedom than mPEG-PF but also can form extensive intermolecular aggregates, therefore, PF-PEG-PF exhibits a significantly lower LCST than mPEG-PF. This paper suggests that topological control is very important in designing a temperature-sensitive polymer.