• Journal of the Korean Applied Science and Technology
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• v.30 no.3
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• pp.567-574
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• 2013

For this research, prepared water soluble milk casein resin and waterborne polyurethane-acrylic resin. Use these resin, this article has been analyzed about change of mechanical properties by increasing amount of casein resin in polyurethane-acrylic resin on coated leather. According to measure data for solvent resistance, WPA(waterborne polyurethane-acrylic resin) resin and WPA-C1, C2, C3(samples of polyurethane-acrylic resin with milk casein resin) had good property. As known in the results, increase of casein constant did not influence to big change of hybrid resin properties. As test of tensile strength, WPA had lowest tensile characteristic(1.598 $kg_f/mm^2$) and WPA-C3 had highest tensile characteristic(1.718 $kg_f/mm^2$). Also best properties of abrasion was WPA-C3(06.021 mg.loss). In elongation case, WPA had best properties(754 %) in this experiment.

• Tribology and Lubricants
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• v.30 no.6
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• pp.343-349
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• 2014

Currently, in order to resist the scratching of the fuel rod surface while fabricating the fuel assembly of the light-water nuclear reactor, we use a solution of nitrocellulose, an explosive material, as a dry lubricant along with its solvent. However, the demand for developing safe and harmless aqueous alternative materials for environment-conservation and field-worker safety has increased. In this study, we demonstrate the preparation of a novel aqueous resin composite using a formulation of aqueous polymeric resin, alcoholic solvent, and water. Subsequently, we characterize this composite on the basis of hardness, adhesive property, and water solubility using plates similar to the fuel rod material. The insertion test of a fuel rod coated with the YS-3 composite shows load values of $18.8-20.5kg/cm^2$, which is comparable with $18.8-20.5kg/cm^2$ of the nitrocellulose coating agent. In addition, the depth and width of longitudinal scratches caused by the YS-3 composite test are 50% higher than those of the standard. We can develop a harmless and safe aqueous dry lubricant to replace the existing NC products through field testing of 264 pieces of fuel rods, after producing 350 kg of the YS-3 prototype. The scratch test for the rod surface showed that weight of chip of YS-3 prototype was smaller than that of NC before and after solvent treatment, indicating the properties of YS-3 prototype was comparable to the counterpart.

• Journal of Korean Society of Forest Science
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• v.48 no.1
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• pp.40-50
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• 1980

This research was carried out to examine the substitutional feasibility of low-priced materials produced in waste of forest instead of wheat flour which is extended for plywood adhesives. Wheat, pine bark, wood flour and pine foliage of coniferous trees or poplar foliage of hardwood species were selected and pulverized into 60-100 mesh minute powder after they were dried at $100-105^{\circ}C$ during 24 hours in the drying oven. The prepared particles as above were added to urea formaldehyde resin, urea-melamine copolymer resin and water soluble phenol formaldehyde resin in the ratio of 10, 20, 30 and 50%. After plywoods were processed by the above extending ratios, shear strength of extended plywoods were analyzed and discussed. The results obtained at this study were summarised as follows; 1. In the case of urea formaldehyde resin, both dry and wet shear strength of plywoods extended by wheat flour were shown the highest value. 2. Dry shear strength of urea-melamine copolymer resin was better than that of urea formaldehyde resin on the whole, while plywoods extended by wheat flour were shown excellent results. 3. Among 10% and 20% extensions of urea-melamine copolymer resin, the best results were shown by poplar leaves powder, wheat powder and wood flour. They had no significant difference statistically. 4. In the case of water soluble phenol formaldehyde resin, although dry shear strength of pine leaves powder was higher than that of wheat flour in the ratio of 10%, there was no significant difference between them in the ratio of 10 and 20%. 5. Among 20, 30 and 50% extensions of water soluble phenol formaldehyde resin, wet shear strength of wood flour and bark powder was higher than that of wheat flour. Wet shear strength of wood flour in the ratio of 10% was shown the same tendency as above.

• The Korean Journal of Ecology
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• v.24 no.2
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• pp.121-123
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• 2001

Gums, resins and gum-resins represent a variety of plant exudates that are highly prized and are extensively used in various industries. The usage of water soluble gums is growing at faster rate as they are excellent suspending agents, dispersants stabilizing agents, emulsifiers and gel forming agents. The gums are made up of carbohydrate polymers, composed of sugar units glycosidically condensed to form large molecules. Resins are non-volatile products, and oxidative products of terpenes or fatty acids, and are of greater commercial importance. They are soluble in water and contrasted with gums, soluble in organic solvents only.

• 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.

• Composites Research
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• v.12 no.6
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• pp.15-21
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• 1999

Carbon fibers were coated with carboxy modified poly(hydroxy ether)(C-PHE, water dispersed), water soluble polymers poly(hydroxy ether ethanol amine)(PHEA) or water insoluble poly(hydroxy ether)(PHE). Interfacial shear strength of polymer coated carbon fibers was measured by micro-droplet tests with vinyl ester resin, and approximately 30 samples were tested. The interfacial adhesion of poly-mers to carbon fibers was also evaluated, and diffusion behavior of polymer films in vinyl ester resin was investigated. The carbon fibers after testing and diffusion samples were analysed by SEM in order to understand adhesion mechanism. Interfacial shear strength of carbon fibers was enhanced by the coating of PHE and C-PHE which have good or marginal solubility in vinyl ester resin, respectively, but not by the coating of PHEA possibly due to the poor solubility in vinyl ester resin.

• Journal of Electrochemical Science and Technology
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• v.12 no.1
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• pp.146-158
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• 2021

This paper reports the preparation of an ink-jet printed flexible electrochromic device based on a water-soluble viologen-functionalized dendrimer. Polyamidoamine (PAMAM) dendrimers were modified with different concentrations of 1-1 bis(propylamine)-4,4'-bipyridylium dibromides to obtain solution-processable electrochromic materials (K1/2 and K1). FTIR, NMR, and elemental analyses are used to characterize synthesized viologens. Moreover, their electrochemical properties were investigated using cyclic voltammetry in an electrolyte solution consisting of 0.1 M HCl to find the optimum viologens. The low-cost ink-jet printer was used to print the prepared water-soluble electrochromic inks onto the ITO coated PET substrate to form desired transparent patterns. The electrolyte was applied on the printed electrochromic ink to make a sandwich with another ITO coated PET to prepare the electrochromic devices (ECD). By applying an electrical potential (0 to -2 V), the transparent ECD's color changed from colorless to blue. The color changes for the optimum ECD (K1), which had more viologen units on the dendrimer, was accompanied by an optical contrast of 47% and 311.5 ㎠C-1 coloration efficiency at 600 nm.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.3
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• pp.337-346
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• 2011

24-hr integrated measurements of water-soluble organic carbon (WSOC) in PM2.5 were made between May 5 and September 25, 2010, on a six-day interval basis, at the Metropolitan Area Air Pollution Monitoring Supersite. A macro-porous XAD7HP resin was used to separate hydrophilic and hydrophobic WSOC. Compounds that penetrate the XAD7HP column are referred to hydrophilic WSOC, while those retained by the column are defined as hydrophobic WSOC. Laboratory calibrations using organic standards suggest that hydrophilic WSOC includes lowmolecular aliphatic dicarboxylic acids and carbonyls with less than 4 or 5 carbons, amines, and saccharides. While the hydrophobic WSOC is composed of compounds of aliphatic dicarboxylic acids with carbon numbers larger than 4~5, phenols, aromatic acids, cyclic acid, and humic-like Suwannee River fulvic acid. Over the entire study period, total WSOC accounted for on average 48% of OC, ranging from 32 to 65%, and hydrophilic WSOC accounted for on average 30.5% (9.3~66.7%) of the total WSOC. Based on the previous results, our measurement result suggests that significant amounts of hydrophobic WSOC during the study period were probably from primary combustion sources. However, on June 9 when 1-hr highest ozone concentration of 130 ppb was observed, WSOC to OC was 0.61, driven by increases in the hydrophilic WSOC. This result also suggests that processes, such as secondary organic aerosol formation, produce significant levels of hydrophilic WSOC compounds that add substantially to the fine particle fraction of the organic aerosol.

• Journal of the Korean Wood Science and Technology
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• v.36 no.2
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• pp.39-45
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• 2008

Formaldehyde and volatile organic compounds (VOCs) are emitted from wood-based panels that have been made using wood particles, wood fiber, wood chips, formaldehyde-based resins and so on. In this study, we examined formaldehyde and total VOCs (TVOC) emission behaviors for plywood overlaid with water-soluble phenolic resin impregnated linerboard (PL), and two kinds of surface materials (decorative veneer and pre-impregnated finishing foil) that were adhered onto the PL that named DPL and PPL. EVA (ethyl vinyl acetate) was used to overlay the decorative veneer and pre-impregnated finishing foil on the plywood with water-soluble phenolic resin impregnated linerboard by a hot press instrument. The debonding test and accelerated aging test were conducted to assess their mechanical properties. Formaldehyde and TVOC emission concentrations were measured using the FLEC method and a VOC Analyzer, respectively. The debonding test results of PL, DPL and PPL were 1.2, 1.5, and $0.5N/mm^2$, respectively. The surface appearance of the samples were not changed after the accelerated aging test. The PL and DPL exhibited reduced formaldehyde and TVOC emission levels, respectively. In the case of PPL, the VOC value was relatively higher than those of PL and DPL.

• Journal of the Korean Wood Science and Technology
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• v.44 no.2
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• pp.231-240
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• 2016

The change in chemical compositions of leachate and medium density fiberboard (MDF) from a laboratory-scale simulated landfill which constructed in a plastic container containing alternating layers of soil and MDF was investigated to evaluate decomposing of MDF in soil. Four treatments were conducted: 1) MDF in soil, 2) MDF only, 3) cured UF resin in soil, and 4) soil only. Molecular weight (MW) distribution of compounds in leachate from soil only treatment did not change over time. In UF resin in soil treatment, the MW distribution shifted to a lower MW distribution over time, while the peak shifted to the left indicated changing to higher MW distribution in leachate from treatment 1 and 2 contained MDF. Higher percent nitrogen in leachate was observed in MDF containing treatments due to the UF resin in the MDF. The percent carbon slightly increased in MDF only while that greatly decreased in MDF in soil treatment maybe due to bacterial activity. The percent of extractable materials from the MDF decreased greatly on day 35 compare to day 0, and subsequently did not change much on day 77. In contrast, percent holocellulose and lignin did not change much over time. No structural change of the wood fiber in MDF occurs during the study. Water-soluble materials from MDF in soil contributed the change in chemical composition of leachate.