• Polymer(Korea)
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• v.29 no.4
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• pp.344-349
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• 2005

Polyurethanes(PUs) were synthesized by reaction of isophorone diisocyanate, acetylbutyl citrate, and 3 types of polycaprolactone diol. Their structures were confirmed by FT-IR and NMR spectrometer. And, their thermal and mechanical properties were measured by TGA ud UTM. The effective network chain lengths ($\bar{M}_c$), measured by compressive modulus apparatus, were about $8000\~24000$ g/mol. As crosslinking density and amount of hard segment increased, tensile strength increased and elongation decreased. As the crosslinking density of PUs increased, thermal property inproved. When the ratio of NCO/OH is 1.1, maximum crosslinking density was achieved.

• Applied Chemistry for Engineering
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• v.16 no.5
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• pp.614-619
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• 2005

The water-soluble defoamers were fabricated by the mixing polyol, modified silicon resin, silicon resin and surfactant. For the defoamers, the various properties such as phase-separation time, viscosity and defoamerability were examined. The phase-saparation time of PPG mixtures was found to be PPG 400>PPG 3,000>PPG 1000. When PPG 1000 was mixed, mixtures represented the excellent defoamerability. The phase-saparation time of silicon resin mixtures was TSF-451-350>TSF-451-200>TSF-451-50. As more of high molecular silicon resin was mixed, the resulting mixtues showed reduced defoamerability. When the TSF-451-50 was mixed, the mixture's volume was increased because of the reduction of solubility. The modified silicon resin was smoothly dispersed in water, but the compatibility with PPG was not good. The defoamerability of surfactant was SPAN 20>SPAN 60>SPAN 80. SPAN 80 showed good miscibility for the silicon resin, but not good for YAS 6406 or PPG 1000.

• Journal of the Korean Applied Science and Technology
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• v.37 no.4
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• pp.1034-1040
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• 2020

The mechanical properties of NATM resin of synthetic polyurethane-epoxy resin for stainless steel were measured by SEM, FT-IR, tensile properties, and specific mass loss by EIS analysis, etc. As interest in eco-friendly medium coatings increased, the Heavy duty coatings were synthesized for various metals such as stainless steel composed of Polyol, MDI, water bored Epoxy resin, filling agent, silicon surfactant, catalyst etc. The coatings of synthetic NATM resin were increased tensile strength due to various temperature change, and the low-Specific Mass Loss was measured in a highly electrolytic solution. In conclusion, the NATM coatings composed of polyurethane and waterbored Epoxy, polyurea resin were synthetic microstructure with cross linkage can be good material for coating of anticorrosion of metal substrates such as stainless steel.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1358-1364
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• 2019

The mechanical properties of Heavy duty resin of synthetic polyurethane-epoxy resin for stainless steel were measured by SEM, FT-IR, tensile properties, and specific mass loss by EIS analysis, etc. As interest in eco-friendly medium coatings increased, the Heavy duty coatings were synthesized for various metals such as stainless steel composed of Polyol, MDI, water bored Epoxy resin, filling agent, silicon surfactant, catalyst etc. The coatings of synthetic Heavy duty resin were increased tensile strength due to various temperature change, and the low-Specific Mass Loss was measured in a highly electrolytic solution. In conclusion, the Heavy Duty coatings composed of polyurethane and waterbored Epoxy resin were synthetic microstructure with cross linkage can be good material for coating of anticorrosion of metal substrates such as stainless steel.

• Elastomers and Composites
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• v.36 no.4
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• pp.268-277
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• 2001

The MDI(4,4'-diphenyl methane diisocyanate) was mixed with PPG, PEG and trimethylolpropane(TMP) respectively to prepare polyurethane resin. The various physical properties were measured for the mixtures. The gel-time was shortened by adding of PEG and TMP The molecular weight made a greater influence on the gel-time than the number of functional groups. The NCO-OH reaction was more active and faster than the NCO-NCO reaction. The hardness was influenced by crosslinking-density and molecular structure. The NCO-OH reactions yielded the flexible films and the NCO-NCO reactions yielded the brittle films. The increase of crystallinity and shrinkage induced the low adhesion ratio but the adding of TMP induced the high adhesion ratio. The flame-retardancy was influenced by quantity and kinds of flame-retardant. IXOL B-251 was the most excellent among the flame-retardants employed in this study. TCCP was partially separated because of the lack of solubility.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.4
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• pp.263-270
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• 2012

Ascorbic acid (Vitamin C) becomes unstable in the aqueous phase by oxygen, light and alkali, etc. The properties are limited in application to cosmetics. The most important factor that determines the destabilization of ascorbic acid in the aqueous phase was tried to understand considering its molecular deformation and degradation. In this study, we changed the polyols and emulsification technique for the stability of ascorbic acid. Then we observed the color and concentration change of ascorbic acid at room temperature and high temperature ($42^{\circ}C$) for 6 weeks and identified the stability using HPLC regularly. As a result, we found that glycerin was the most appropriate polyol for stability of the ascorbic acid. Also the technique of nonaqueous emulsification stabilized ascorbic acid than P/S emulsification. Also, P/S emulsification, glycerin was more stable than propylene glycol. By the results we suggest that ascorbic acid could be stabilized by nonaqueous emulsification method and this data could be applied to stabilization methods for cosmetic products.

• Journal of the Korean Applied Science and Technology
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• v.31 no.2
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• pp.238-243
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• 2014

The mechanical properties of NATM resin were measured by SEM, FT-IR spectra, tensile properties, mole ％ of [NCO/OH], and particle size analyzer on stainless steel. Growing concerns in the environment-friendly NATM resin, we have synthesized the solvent-free NATM resin to be coating on metals such as stainless. The properties of the synthesized NATM resin to be contained polyols, MDI, silicone surfactant, fillers and crosslink agents(diethyltoluene diamine, anhydrosorbitol), that they have highly stronger in intensity and longer durability than general NATM resin to be contained polyols, IPDI, silicone surfactant, fillers in general packing materials and coatings. The rigid segments of polyurethane in mechanical properties of coatings were due to cross linkage and the increase mole % of [NCO/OH]. In conclusion, the NATM microstructure with cross linkage can be good material for coating of anticorrosion of metal substrates such as stainless steel.

• Applied Chemistry for Engineering
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• v.8 no.2
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• pp.197-203
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• 1997

The effect of additives on the mechanical properties of polyurethane foam were investigated. The resin used in this study was prepared by adding catalyst, surfactant and cross-linker to both KONIX FA-703 polyether polyol(80%) and KONIX FA-733 polyether polyol(20%). The polyurethane was foamed by adding equivalent amount of isocyanate(TDI-80, prepolymer M-200, pure MDI) to the resin and was used in property measurements after 72 hours hardening. The physical properties of polyurethane foam were investigated in terms of density, tensile strength, tear strength, elongation, sound absorption coefficient and gel profile measurements. The effects of surfactant on the cell size was investigated by scanning electron microscopy(SEM). The sound absorption coefficient was directly related to the cell size. The physical properties were improved with increasing amount of surfactant(L-5309) until 1.0 part per hundred polyol(1.0pphp).

• Journal of the Korean Applied Science and Technology
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• v.14 no.3
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• pp.23-28
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• 1997

The phase diagram for the surfactant mixture system of N-dodecanocyl-N-methyl amido polyolcarboxyl alkyl ether(DGC)/N-dodecanocyl-N-alkyl glucamine(DG)/water was studied usingpolarized microscopy, differential scanning calorimetry(DSC) and rheological measurements respectively. Using polarized microscopy, the textures of liquid crystal phases obtained at various surfactantconcentrations were investigated as a function of surfactant concentration and temperature, and phasetransitions between anisotropic liquid crystal phases and isotropic liquid phase were examined usingDSC measurements. Viscoelastic properties of surfactant solutions determined between hexagonal andlamellar liquid crystal phase by rheological measurements were approximately consistent with the resultsobtained by polarized microscopy and DSC. In the study for the phase of DGC/DG(5:5 mol ratio)/water system. It could be found that the hexagonal liquid crystal phase appeared at 25${\sim}$60wt％ ofsurfactant, the cubic liquid crystal phase at 50${\sim}$65wt％ and the lamellar crystal phase at above 70wt％.

• Journal of the Korean Applied Science and Technology
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• v.31 no.3
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• pp.525-533
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• 2014

ZnO has attracted much attention such as photocatalysts, sensors, piezoelectricity and etc. At present, an economical and rapid synthesis route based on the efficient microwave polyol process is used to synthesized metal-doped ZnO nanoclusters. Diethylene glycol has a property of high polarizability, and is an excellent microwave absorbing agent, thus leading to a high heating rate and a significantly shorter reaction time. In this study, metal-doped ZnO nanoclusters are obtained with different seed volumes, when zinc acetate dihydrate is used as a precursor, and metal acetate hydrate is used as a doped-metal and diethylene glycol is used as a solvent. The obtained metal-doped ZnO nanoclusters were characterized by FE-SEM, XRD, Raman and PSA.