• Journal of Adhesion and Interface
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• v.18 no.1
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• pp.8-12
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• 2017

In this study, waterborne polyurethane was synthesized with polyester polyol, poly(propylene carbonate) (PPC), 4,4-dicyclohexylmethane diisocyanate ($H_{12}MDI$) and dimethylol propionic acid (DMPA) to improve the water resistance. The properties of the synthesized waterborne polyurethane using poly(propylene carbonate) (WPUP) was evaluated through FT-IR, GPC, DSC and UTM. The mechanical properties were increased with the increase in the amount of PPC. When the ratio of polyester polyol to poly(propylene carbonate) is 9:1, the highest water resistance was showed.

• Journal of Adhesion and Interface
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• v.13 no.4
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• pp.163-170
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• 2012

Although ${\beta}$-cyclodextrin (${\beta}$-CD) has been used as medicine, agrichemical, food, cosmetic, antioxidant, anti-volatile agent, anti-hygroscopic agent, fading-protecting agent, and emulsifier due to its ability to form inclusion complex by enclosing another molecule (guest molecule), it has been restricted in practical application because of its low solubility in water and organic solvent. In this study, ${\beta}$-CD derivative as a new polyol with inclusion characteristics against Bisphenol A and cyclopropane, foaming agent for polyurethane (PU), and with improved solubility was synthesized, characterized and used to formulate rigid PU foam with better thermal conductivity and compressive strength compared to that from commercial polyols.

• Journal of Adhesion and Interface
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• v.22 no.2
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• pp.39-46
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• 2021

Waterborne polyurethanes (WPU) was synthesized using polyester polyol and polycarbonate polyol containing 3-Methyl-1,5-pentanediol (MPD) in a branched structure. To compare physical properties, WPUs were synthesized using polyester polyol obtained from 1,4-butanediol (BD) and adipic acid and polycarbonate polyol obtained from 1,6-hexane diol (HD)/ 1,4-butanediol (BD). This study investigated the effect of polyol molecular structure (molecular structure in soft segments) on the physical properties of WPUs. In the case of WPUs synthesized using polyols containing MPD, 100% modulus and tensile strength were lower than that without MPD, and elongation was higher. The transparency of WPU films with MPD were slightly better than WPU films without MPD.

• Journal of Adhesion and Interface
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• v.23 no.1
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• pp.8-16
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• 2022

In this study, self-healable waterborne polyurethane (SH-WPU) as shoes and coating materials with self-healable disulfide functionalities was synthesized by mixing polyether polyol to impart excellent durability and heat resistance and polycarbonate polyol to impart excellent mechanical properties. The synthesized SH-WPU was characterized by fourier transform-infrared spectroscopy (FT-IR), and physical and self-healing properties were confirmed through universal testing machine (UTM) and scanning electron microscope (SEM) measurements. Tensile strength and hardness were increased and elongation was decreased by using polycarbonate polyol. In addition, as a result of comparison of thermal properties, thermal stability has been increased as the content of polycarbonate polyol increased. The healing efficiency showed the highest efficiency when poly(tetramethylene ether)glycol : polycarbonate polyol = 0.75 : 0.25, and it was confirmed that the damaged part was healed through surface observation using a microscope and SEM.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1290-1292
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• 2009

Modified-polyol protocol was utilized for synthesis of green-emitting ($^5D_4-^7F_j$ transitions of $Tb^{3+}$ ion) nanocrystalline $LaPO_4:Ce^{3+}$, $Tb^{3+}$ phosphors. Experimental parameters including chemical composition and annealing temperature were optimized to produce highly efficient, uniformly sized nanophosphors. Spin-deposited layer of $LaPO_4:Ce^{3+}$, $Tb^{3+}$ nanophosphors on glass substrate exhibited a transmittance of more than 80 %, indicating their efficacy for transparent display.

• Journal of the Korean Applied Science and Technology
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• v.26 no.2
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• pp.213-223
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• 2009

Conventional additives were added to a newly synthesized base oil to create synthetic lubricants. Commercial polyol ester prepared in this laboratory were obtained as esterification of 1,1,1-trimethylol propane and respectively. This newly synthesized base oil had a variable chemical structure that could achieved the following properties; oxidation or thermal stability, low temperature fluidity, and higher flash points. When compared with commercial mineral lubricants, the synthetic lubricants show superior thermal and oxidation stability, and anti-wear properties.

• Elastomers and Composites
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• v.52 no.1
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• pp.81-85
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• 2017

In order to improve the water resistance, we synthesized waterborne polyurethane by using polyester polyol, poly(propylene carbonate) (PPC), 4,4'-dicyclohexylmethane diisocyanate ($H_{12}MDI$), and dimethylolpropionic acid (DMPA). The properties of the synthesized waterborne polyurethane using poly(propylene carbonate) (WPUP) were evaluated by FT-IR, $^1H-NMR$, GPC, DSC, TGA, and UTM. The mechanical properties increased while the adhesion properties decreased with the increase in the amount of PPC. The highest water resistance was shown when the ratio of polyester polyol to PPC was 9:1.

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.313-318
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• 2003

Vitamin C's function and mechanism are comparatively well known among the several kinds of vitamins. Inhibition of free radical. promotion of collagen synthesis, restraint of melanin formation and resolution of melanin are its main functions. But Vitamin C is very easy to oxidize by heat, moisture or air so it causes stability problem to make formulation. To solve these problems unique formulating method or derivatives using method could be effective. Object: First, stabilize 10% of Ascorbic acid as polyol/silicone emulsion and try to make polyol/silicone/polyol anhydrous multiple emulsion secondly. And then, encapsulate with porous power to enhance the stability of Ascorbic Acid from formulating method.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2004.11a
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• pp.60-60
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• 2004

• Proceedings of the Materials Research Society of Korea Conference
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• 2000.11a
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• pp.142-142
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• 2000