• Journal of Adhesion and Interface
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• v.17 no.2
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• pp.67-71
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• 2016

In this study, low-viscosity polyurethane hot-melt were synthesized with polyether polyol / polyester polyol, 4,4-dicyclohexylmethane diisocyanate ($H_{12}MDI$), 2-butanone oxime (MEKO) to improve the properties and peel strength. The properties of the synthesized low-viscosity polyurethane hot-melt was evaluated through FT-IR, viscosity meter and UTM. When the content of the reactive diluent increases and the NCO-blocked prepolymer decreases, the viscosity of low-viscosity polyurethane hot-melt adhesive was increased. When the ratio of OH-terminated oligomer, NCO-blocked prepolymer and content of reactive diluent is 1 : 0.5 : 0.5, low-viscosity polyurethane hot-melt showed 1.1 kgf/cm peel strength.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.5
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• pp.437-447
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• 2012

Ceria ($CeO_2$) was used to scavenge free radicals which attack the membrane in the polymer electrolyte membrane water electrolysis (PEMWE) circumstance and to increase the duration of the membrane. In order to improve the electrochemical, mechanical and electrocatalytic characteristics, engineering plastic of the sulfonated polyether ether ketone (SPEEK) as polymer matrix was prepared in the sulfonation reaction of polyether ether ketone (PEEK) and the organic-inorganic blended composite membranes were prepared by sol-gel casting method with loading the highly dispersed ceria and cesium-substituted tungstophosphoric acid (Cs-TPA) with cross-linking agent contents of 0.01 mL. In conclusion, CL-SPEEK/Cs-TPA/ceria (1%) membrane showed the optimum results such as 0.130 S/cm of proton conductivity at $80^{\circ}C$, 2.324 meq./g-dry-membrane of ion exchange capacity and mechanical characteristics, and 65.03 MPa of tensile strength which were better than Nafion 117 membrane.

• Membrane Journal
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• v.25 no.5
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• pp.447-455
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• 2015

In this study, Polysulfone (PSf) and polyetherimide (PEI) as the anion exchange polymers were aminated in the different ratio whereas the polyether ether ketone (PEEK) as the cation exchange polymer was sulfonated. The bipolar membranes of SPEEK (sulfonated PEEK)/APSf (aminated PSf) and SPEEK/APEI (aminated PEI) were prepared by the double-casting method. The surfaces of bipolar membranes were fluorinated in accordance with the amination ratio and applied to produce the hypochlorite. As the amination increased, the hypochlorite concentration is also increased. Typically, for SPEEK/APSf 3 : 1 membrane, the produced hypochlorite concentration was 61.0 ppm and its durability was 220 min for the non-fluorinated membrane while for the fluorinated membrane, the concentration of 58.6 ppm and its durability lasted 570 min. Also for SPEEK/APEI 3 : 1 membrane, the hypochlorite concentrations of 60.1 ppm and 58.3 ppm for before- and after-fluorination, respectively were observed whereas the durability was remarkably developed from 150 min to 440 min. Therefore, the surface fluorination takes an important role for the development of the membrane durability.

• Membrane Journal
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• v.29 no.1
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• pp.1-10
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• 2019

Poly(ether block amide) (PEBA) is one of the commercially important class of block copolymer very much suitable specifically for $CO_2$ separation. Gas separation membrane need to have good mechanical strength as well as high gas permeability. The crystalline polyamide (PA) block provides the mechanical strength while the rubbery polyether (PE) group being $CO_2$-philic facilitate $CO_2$ permeation though the membrane. Composition of thermoplastic and rubbery phase in the polymer are changed to fit into suitable gas separation application. Although PEBA has good permeability, the selectivity of the membrane can be enhanced by incorporating molecular sieve without affection much the gas permeability. Mixed matrix membrane (MMM), a class of composite membrane combine the advantage of polymer matrix with the inorganic fillers. However, there are some disadvantages based on the compatibility of the inorganic fillers and polymeric phase. This review covers both the advantage and limitations of PEBA block copolymer based composite membrane.

• Journal of Adhesion and Interface
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• v.23 no.4
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• pp.137-143
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• 2022

In this study, the polyurethane acrylates (PUA) resin with good adhesive and flexibility for adhesive for shoes and clothing were synthesized using that poly(tetramethylene adiphate glycol) (PTAd), poly(tetramethylene ether glycol) (PTMG) as polyester polyol and polyether polyol respectively, including 4,4'-methylene diphenyl diisocyanate (MDI), isophorone diisocyanate (IPDI), 1,4-butandiol (1,4-BD), 2-hydroxyethyl methacrylate (2-HEMA) and dibutyl amine (DBA). The effect of polyol blend in the polyurethane acrylate on thermal and mechanical properties, adhesion strength and flexural strength were studied. The glass transition temperature (T_g) of PUA was confirmed in range of -70~-40 ℃. In addition, the glass transition temperature (T_g), decomposition temperature (T_d), tensile strength adhesion strength and heat resistance were increased as increasing of PTAd amount while the elongation, water resistance and flexural properties were decreased. The synthesized polyurethane acrylate with 5:5 ratio of PTAd and PTMG indicated the highest adhesion strength and flexural properties.

• Bulletin of the Korean Chemical Society
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• v.28 no.10
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• pp.1777-1780
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• 2007

The synthesis of well-defined dendrons based on aliphatic polyether dendritic cores and glassy polystyrene peripheries is described. The synthetic route involves a combination of living anionic polymerization and a stepwise convergent method consisting of iterative Williamson etherification and hydroboration/oxidation reactions. On the basis of molecular weight, as characterized by gel permeation chromatography (GPC), the first generation dendron (Generation-1) shows a random coil conformation like a linear polystyrene, while higher generations (Generation-2 and 3) reveal globular forms in solution.

• Proceedings of the Membrane Society of Korea Conference
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• 1993.10a
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• pp.61-62
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• 1993

고분자 분리막의 투과성과 선택성을 향상시키기 위하여 IPN막, 고분자/액정 복합막을 다양한 기능을 가진 재료가 개발되고 있다. 본 연구에서는 알칼리메탈이온을 분리하기 위하여 고분자 지지체에 운반체로써 crown ether(macro-cyclic polyether)류를 분산시킨 고분자/운반체 복합박막을 제조하였다. 고분자/운반체 복합박막은 고분자와 운반체의 혼합용액을 수면에 전개시켜 제조하였다. 고분자는 PVC(M.W 60000, Aldrich), PS(M.W 280000, Aldrich)와 CA(M.W 30000, Sigma)를 사용하였고, 운반체로는 crown ether 중 $K^+$이온과 선택성을 가지는 18-Crown-6(Sigma)를 사용, 고분자와 18-Crown-6의 증량분을 달리하는 혼합용액을 제조하였다. 이때 용매는 Tetrahydrofuran를 사용하였다. 수면에 생성된 박막을 다공성 지지막에 적층시킨 후 감압 건조시켜 복합막을 제조하였다. 고분자와 운반체가 혼합되어 있는 용액의 점도와 표면장력을 각각 fluid spectrometer와 tensionmeter를 사용, 용액이 수면위에서 완전한 막을 형성하면서 분산될 수 있는지 조사하였으며, 고분자 지지체에 분산 고정된 운반체의 분산형태와 표면농도를 조사하기 위하여 ESCA를 이용하였다.

• Textile Coloration and Finishing
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• v.10 no.5
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• pp.32-38
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• 1998

Glycolides were polymerized by PPG or Pluronic(PN) to give A-B-A block copolyesters consisting of polyglycolide(A) and polypropylene glycol(B) or polyglycolide(A) and PN (B). Lactones were easily copolymerized with polyethers by ester interchange reaction even in the absence of catalyst. It is because PPG and PN are telechelic polyethers having hydroxy groups on their both ends. When the feed ratio of PPG(M$_{n}$=4,000) and PN(M$_{n}$=11,500) were over 5 and 10 wt% .elative to glycolide, respectively, the polymerization of glycolide took place from the terminus hydroxy groups of PPG or PN to produce the desired A-B-A block copolymers in high yields. The molecular weights of the copolymers, which estimated from the monomer conversions and the feed ratios of PPG and PN, could be controlled by changing the kind of terminus hydroxy of polyether and the feed molar ratio of PPG and PN. PN.

• Journal of Pharmaceutical Investigation
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• v.17 no.2
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• pp.75-78
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• 1987

The release rate of heparin from monolithic devices composed of raffinose, ${\beta}-cyclodextrin$, polyethylene oxide (Mw 20,000, PEO), and hydrophobic polyether urethane (biomer) was investigated. Water soluble raffinose, ${\beta}-cyclodextrin$, and PEO blended into the biomer provided a controlled release of heparin. The release rate of heparin could be controlled by the content of raffinose, ${\beta}-cyclodextrin$, and PEO in the devices. The mechanism of release rate increased by the raffinose, ${\beta}-cyclodextrin$, and PEO may result from the formation of channels and pores in the biomer matrices following the swelling and the change in the physical structure of polymer net work. Hydrophobic polyurethane containing raffinose, ${\beta}-cyclodextrin$, and PEO can provide a hydrophilic antithrombogenic material for prolonged release of heparin.

• Journal of the Korean Applied Science and Technology
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• v.27 no.1
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• pp.87-92
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• 2010

Silicone surfactants are widely used in many industrial area because of its thermal stability and lower foaming property. But it has limitation to expand the application because of migration and bubble generation issues when it is mixed with organic surfactant. In this study, epoxy functionalized fluoro-silicone surfactant, perfluoro glycidoxypropyl polyether siloxane(PFGES), was synthesized using hydrosilylation reaction among perfluoro methyl hydrogen siloxane, allyl glycidyl ether, and allyl ployether in order to get lower surface tension, better thermal stability than conventional silicone surfactant, and reactivity with anhydride function.