• Journal of Adhesion and Interface
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• v.21 no.1
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• pp.14-19
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• 2020

In this study, we synthesized a self-photocuring intermediate(SPI) by Michael addition reaction and synthesized polyurethane acrylate oligomer. Analysis and physical properties of the synthesized SPI and polyurethane acrylate oligomer were confirmed by FT-IR, NMR and UTM. As the content of the SPI increased, the tensile strength increased and the elongation decreased. In addition, since the film was hydrophobic, the surface energy tended to decrease. When the content of the SPI was 40 wt%, adhesion, processability, and pencil hardness were excellent, and solvent resistance was excellent overall.

• Polymer(Korea)
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• v.31 no.2
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• pp.111-116
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• 2007

Polyurethane modified acrylate $(PUA)/SiO_2$ hybrid films were prepared by ultraviolet curing and their surface properties were investigated by hardness and adhesion test. The films were examined by the manipulation of mole-ratio of organic to inorganic components. Under the silica content controlled, highly desirable films were achieved and scratch resistance and hardness property of film were also enhanced, which indicates that the crosslinked silica particles are homogeneously dispersed within PUA film.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.252-254
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• 2002

In this study, polyurethane acrylate macromer was synthesized and it was used in a gel polymer electrolyte, and then its electrochemical performances were evaluated. LiCoO$_2$/GPE/MCF cells were also prepared and their performances depending on discharge currents and temperatures were evaluated. ionic conductivity of the gel polymer electrolyte with PUA at room temperature and -20$^{\circ}C$ was ca. 4.5 x 10$\^$-3/ S/cm and 1.7${\times}$10$\^$-3/ S/cm, respectively. GPE was stable electrochemically up to 4.5 V vs. Li/Li$\^$+/. LiCoO$_2$/GPE/MCF cell showed a good high-rate and a low-temperature performance.

• Journal of Environmental Science International
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• v.27 no.11
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• pp.1023-1028
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• 2018

Shape memory materials are widely used in high-tech industries. Although shape memory polymers have been developed, they have a disadvantage, only unidirectional resilience. Shape memory polymers with bi-directional recovery resilience have been actively studied. In this study, a bidirectional shape memory polyurethane was synthesized using poly(${\varepsilon}$-caprolactone) diol, methylene dicyclohexyl diisocyanate, and hydroxyethyl acrylate. The first physical curing occurred between hard segments and hydrogen bondings when the solution was dried. The second curing in acrylate groups was performed by UV exposure. A degree of curing was analyzed by infrared spectroscopy. The shape memory properties of 2 step-cured polyurethanes were investigated as a function of UV curing time.

• Applied Chemistry for Engineering
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• v.20 no.1
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• pp.52-61
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• 2009

In this study, TAPEH (t-amyl peroxy 2-ethyl hexanoate) was selected for the reaction initiator which is a core factor for developing acrylic polyol binder. Tone M100 (caprolactone acrylate), 4HBA (4-hydroxy butyl acrylate), and 2HEMA (2-hydroxy ethyl methacrylate) were used for hydroxy-monomers. To check the applicability of raw materials mentioned above into the binders of 2 components acrylic polyurethane paint and reduce the VOC, the reactivity and film performance by different kinds of aliphatic polyisocyanate hardeners which are already generalized were reviewed. As the Tin-based catalyst has been regulated, the comparison test of reactivity and performance between the conventional catalyst and non-toxic metal catalyst recommended as the alternative was conducted as well. As a result, we were able to obtain the basic data which are necessary for applying 2 components high solid polyurethane paint and also reached a conclusion that it can be applied for developing new paints in terms of high performance, workability and environmental care.

• Proceedings of the Korean Fiber Society Conference
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• 1999.04a
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• pp.75-78
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• 1999

• Fibers and Polymers
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• v.2 no.3
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• pp.122-128
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• 2001

UV-curable polyurethane acrylate prepolymers were prepared from diisocyanates [isophorone diisocyanate (IPDI), 2,4-toluene diisocyanate (TDI), or 4,4'-dicyclohexylmethane diisocyanate (H$_{12}$MDI)], diols [ethylene glycol (EG), 1,4-butane diol (BD), or 1,6-hexane diol (HD)], polypropylene glycol as a polyol. UY-curable mixtures were formulated from the prepolymer (90 wt%), reactive diluent monomer trimethylol propane triacrylate (10 wt%). and photoinitiator 1-hydroxycy-clohexyl ketone (3 wt% based on prepolymer/diluent). The effects of different diisocyanates/low molecular weigh dial on the dynamic mechanical thermal properties and elastic recovery of UV-cured polyurethane acrylate films were examined. The tensile storage modulus increased a little in the order of EG > BD > HD at the same diisocyanate. Two loss modulus peaks for all samples are observed owing to the glads transition of softs segments ($T_gh$) and the glass transition temperature of hard segments ($T_gh$). For the same diisocyanate, $T_gh$, decreased, however, $T_gh$ increased, in the order of HD > BD > EG. The elastic recovery also increased in the order of HD > BD > EG at the same diisocyanate. In case of same diols, $T_gh$ increased in the order of $H_12$MDl > TDI > IPDI significantly. The ultimate elongation and elastic recovery increased in the order of TDI > IPDI > $H_12$MDl at the same diol.l.

• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.632-638
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• 2012

Waterborne polyurethane dispersions (PUD) were synthesized from isophorone diisocyanate (IPDI), polycarbonate diol (PCD) and dimethylol propionic acid (DMPA) as starting materials. Subsequently, waterborne polyurethane-acrylic hybrid solutions were prepared by reacting the PUD with different amounts of the mixture of acrylate monomers, HEMA (2-hydroxyethyl methacrylate) and MMA (methyl methacrylate). As a result, the average particle size of waterborne polyurethane-acrylic hybrid solutions was increased with increasing the addition amounts of acrylate monomers. Also, the prepared coating films from waterborne polyurethane-acrylic hybrid solutions showed better abrasion resistance and chemical resistance than those of pure PUD.

• Journal of the Korean Wood Science and Technology
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• v.27 no.3
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• pp.31-38
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• 1999

This paper deals with a coating technique of hardening surface layer of softwood{Larix leptolepis) flooring board to improve its surface properties such as hardness and abrasion resisitance without spoiling its exellent qualities such as beautiful color tones and great strength. For surface hardening of the wood, polyurethane wood sealer was used as under coat, polyurethane sanding sealer as intermediate coat, and UV-curing epoxy acrylate and urethane acrylate varnishes as top coat. The hardness of the wood was improved by the coating treatment and it was similar to that of high density hardwood such as oak, keruing. The abrasion resistance of the coated wood was greatly improved by UV curing epoxy acrylate or urethane acrylate varnishes. Adhesion properties and impact resisitance of the coated wood surface were also good. It was suggested that the well-coated larch wood could be used as interior flooring board as substitute for hardwood such as keruing.

• Applied Microscopy
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• v.50
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• pp.26.1-26.3
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• 2020

The biocompatible polyurethane acrylate (PUA) nanopillars were fabricated by soft lithography using three different sizes of nanobeads (350, 500, and 1000 nm), and the human adipose-derived stem cells (hASCs) were cultured on the nanopillars. The hASCs and their various behaviors, such as cytoplasmic projections, migration, and morphology, were observed by high resolution images using a scanning electron microscope (SEM). With the accurate analysis by SEM for the controlled sizes of nanopillars, the deflections are observed at pillars fabricated with 350- and 500- nm nanobeads. These high-resolution images could offer crucial information to elucidate the complicated correlations between nanopillars and the cells, such as morphology and cytoplasmic projections.