• Journal of the Korean Applied Science and Technology
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• v.28 no.3
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• pp.359-366
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• 2011

In this study we experimented that how polyurethane effect to acrylic-polyurethane resin in Full-Grain leather coatings. First of all, we consummated waterborne acrylic emulsion and waterborne polyurethane resin, Than we prepared F.G leathers which were coated by acrylic resin and acrylic-polyurethane resins. According to measured data for solvent resistance, acrylic resin and acrylic-polyurethane resins had good property. Sample a(WAC) had most low strength($2.10kg_f/mm^2$) and sample d(WAC 93 : WPU 7) had most high strength($3.41kg_f/mm^2$). Also we knew that most good property of abrasion is d(47.4 mg). In elongation case, a(WAC) had most good result(645 %) in this experiment.

• Journal of the Korean Applied Science and Technology
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• v.28 no.2
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• pp.203-212
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• 2011

In this study we experimented that how chain extension influences to waterborne urethane-acrylic hybrid resin for leather garment coatings. We knew that polyurethane-acrylic hybrid resins had 5 grades of solvent resistance. Tensile strength measured in the polyurethane-acrylic resin(EDA 5.37 g, 1.928 kgf/$mm^2$) had the most strong strength. Also polyurethane-acylic hybrid resin(EDA 5.37 g. 30.2 mg. loss) had better result than other hybrid resins. EDA contents higher, we obtained low elongation and low flexibility. In this result, chain extension of waterborne polyurethane-acrylic hybrid resin showed the effect in leather coating with ratio of EDA.

• Journal of the Korean Applied Science and Technology
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• v.27 no.2
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• pp.188-195
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• 2010

In this study, we experimented that how to synthesis waterborne urethane-acrylic hybrid resin for leather coatings. First of all, We had analyzed data by FT-IR, SEM and TGA for the machanical properties. By TGA analysis polymers showed heat distortion temperature. and by FT-IR measurement we confirmed that synthesis of urethane and acrylic. In the experiment, solvent resistance, polyurethane and acrylic grades 4-5 showed both a high. Tensile strength measured in the waterborne polyurethane > Acrylic emulsion showed strength in the order. Films were obtained by coating the water born resin on leveled surfaces and allowing them to dry at room temperature for 72hrs. After demolding, the films were kept in a desiccator to avoid moisture contant at $25^{\circ}C$ for 45hrs before the measurements. In this result, the mechanical propersies of waterborne polyurethane-acrylic hybrid resin showed that how effect to resin in leather coating between polyurethane content and acrylic content. Therefore, acrylic emulsion had most high solvent resistance glade and waterborne polyurethane had good result in abrasion test and tensile strength.

• Journal of the Korean Applied Science and Technology
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• v.28 no.1
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• pp.109-117
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• 2011

In this study, we experimented that how influence chain extension to waterborne urethane-epoxy hybrid resin for leather garment coatings. First of all, We had analyzed datas by FT-IR, SEM and machanical properties. By instruments analysis measurement we confirmed that synthesis of epoxy and hybrid resin. In this experiment we knew that polyurethane-epoxy hybrid resin have 5 grades of solvent resistance. Tensile strength measured in the polyurethane-epoxy resin(EDA 5.37g, 2.386 $kg_f/mm^2$) had the most strong strength.. Also polyurethane-epoxy hybrid resin had better result(EDA 5.37g. 37.4 mg. loss) than other hybrid resins. As hight proportion of EDA in hybid resin, we obtained low elongation and low flexibility. In this result, chain extension of waterborne polyurethane-epoxy hybrid resin showed that how effect in leather coating by ratio of EDA.

• Journal of the Korean Applied Science and Technology
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• v.27 no.3
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• pp.325-336
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• 2010

In this study, we experimented that how to synthesis waterborne urethane-epoxy hybrid resin for leather garment coatings. First of all, We had analyzed datas by FT-IR, SEM and TGA for the machanical properties. By instruments analysis measurement we confirmed that synthesis of urethane and epoxy. In this experiment we knew that polyurethane and urethane-epoxy hybrid resin have 4~5 grades of solvent resistance. Tensile strength measured in the urethane-epoxy resin(epoxy 12%, 2.033$kg_f/mm^2$) had the most strong strength than polyurethane(1.833 $kg_f/mm^2$) emulsion samples. Also urethane-epoxy hybrid resin had better result than polyurethane in acid resistance and abrasion test. As hight proportion of epoxy in hybid resin, we obtained low elongation and low flexibility. In this result, the mechanical properties of waterborne polyurethane-epoxy hybrid resin showed that how effect in leather coating by ratio of epoxy emulsion.

• Polymer(Korea)
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• v.36 no.5
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• pp.622-627
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• 2012

This study focuses on mechanical property enhancement and volatile organic compounds (VOCs) reduction characteristic of environmentally-friendly waterborne coatings. We synthesized a series of organic-inorganic hybrid waterborne polyurethanes by using poly(tetramethylene glycol) 2000, polycarbonate diol 2000, isophorone diisocyanate, dimethylolpropionic acid and titanium dioxide. The study on the effects of the R ratio([NCO]/[OH]) and inorganic contents on environmentally-friendly waterborne coatings showed that the R ratio with more than 1.5 is appropriate due to arrangement of hardsegments. The applied $TiO_2$ on films reduced volatile organic compounds (VOCs).

• Journal of the Korean Applied Science and Technology
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• v.30 no.2
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• pp.264-271
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• 2013

In this study, we have synthesized waterborne polyurethane dispersion(WPU) and analyzed mechanical properties of WPU film and leather coatings in different content of monoammonium phosphate. According to the measured data by DSC, sample WPU-AM3 which included high content of monoammonium phosphate showed the highest Tm at $382^{\circ}C$. All samples had good solvent resistance. In tensile tests, WPU-AM3($2.130kg_f/mm^2$) had the lowest physical properties. Also abrasion resistance properteis and elongation properties were investigated, WPU-AM3 had lowest physical properties with 52.07 mg.loss for abraison and 615 % of elongation.

• Elastomers and Composites
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• v.57 no.3
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• pp.100-106
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• 2022

Waterborne polyurethane-acrylate(WPUA) dispersions were prepared by surfactant-free emulsion polymerization in a two-step process. In the first step, polytetrahydrofuran, isophorone diisocyanate, dimethylol proponic acid, and 2-hydroxyethyl methacrylate were used to synthesize a vinyl-terminated polyurethane prepolymer. In the second step, styrene, methyl methacrylate, butyl acrylate, and different multi-functional crosslinkers were copolymerized. 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, and pentaerythritol tetraacrylate were used as the crosslinkers, and their effect on the mechanical and thermal properties of WPUA was investigated. Overall, as the number of functional groups of the cross-linker increased, the gel fraction improved to 79.26%, the particle size increased from 75.9 nm to 148.7 nm, and the tensile strength was improved from 5.86 MPa to 12.40 MPa. In thermal properties, the glass transition temperature and decomposition temperature increased by 9.9℃ and 18℃, respectively. The chemical structures of the WPUA dispersions were characterized by Fourier-transform infrared spectroscopy. The synthesized WPUA has high potential for applications such as coatings, leather coatings, adhesives, and wood finishing.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.162-163
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• 2021

To prepare the waterborne silicone acrylic resin coatings, acrylic resin was prepared by a radical polymerization. Glass transition temperature(Tg) of the acrylic copolymer was fixed at 30℃ and the contents of tertiary amine monomer(DMAEMA), were varied to be 5, 10, 15 and 20 wt%, hydroxyl monomer, and carboxyl monomer were fixed 10 wt%, and 4 wt% respectively. γ-Glycidoxypropyltrimethoxysilane(GPTMS) containing epoxy group was used for curing agents. The eqivalent ratio of amine to epoxy was 1:1. The prepared coatings exhibited excellent adhesion to various substrates, and various physical properties of the coatings were satisfactory. The gloss retension and color difference were improved at low tertiary amine concentration. The coatings containing 10wt% tertiary amine concentration have especially good weather resistant properties.

• Fibers and Polymers
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• v.3 no.4
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• pp.153-158
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• 2002

A series of waterborne polyurethanes (WBPU) were prepared from 4,4-dicyclohexylmethane diisocyanate ($H_{12}$MDI),2,2-bis(hydroxylmethyl) propionic acid (DMPA), othylenediarnine (EDA), triethylamine (TEA), and triblock glycol [TBG, ($\varepsilon$-caprolactone)$_{4.5}$-poly(tetramethylene ether) glycol (MW= 2000)-($\varepsilon$-caprolactone)$_{4.5}$: $(CL)_{4.5}$-PTMG-$(CL)_{4.5}$, MW=3000] as a soft segment. Two melting peaks of TBG at about 14$^{\circ}C$ and 38$^{\circ}C$ were observed indicating the presence of two different crystalline domains composed of CL and PTMG dominant component. The effect of soft segment content (60-75 wt%) on the colloidal properties of dispersion, and thermal and mechanical properties of WBPU films, the water vapor permeability (WVP) and water resistance (WR) of WBPU-coated Nylon fabrics, and the adhesive strength of WBPU- coated layer and Nylon fabrics was investigated. As soft segment contents increased, the water vapor permeability of WBPU- coated Nylon fabrics increased from 3615 to 4502 g/$m^2$day, however, the water resistances decreased from 1300 to 500 mm$H_2$O.O.