• 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.

• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.614-620
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• 2012

Polyurethane prepolymers were prepared from poly (carbonate diol), isophrone diisocyanate and dimethylol propionic acid. Then, aniline terminated waterborne polyurethane dispersion (ATPUD) was synthesized by capping the NCO group of the prepolymer with aniline monomer. Subsequently, ATPUD and waterborne polyurethane dispersion (PUD), respectively, were blended with conducting polymer, poly (3,4-ethylenedioxythiophene)/polystyrene sulfonate [PEDOT/PSS], to yield antistatic coating solutions, and the mixture was coated on the polycarbonate substrates. At adequate addition amounts of PEDOT/PSS less than or equal to 2.5 g, the surface resistances ($1.0{\times}10^{11}{\sim}2.5{\times}10^8{\Omega}/cm^2$) of coating films from ATPUD showed better electronic conductivities than those ($5.0{\times}10^{11}{\sim}6.3{\times}10^9{\Omega}/cm^2$) from PUD. However, at excess amount of PEDOT/PSS of 3.0 g, the surface resistance from ATPUD showed similar electronic conductivity with that from PUD.

• 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.

• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.639-645
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• 2012

Waterborne polyurethane dispersion (PUD) was synthesized by capping the NCO groups of polyurethane prepolymers, prepared from isophorone diisocyanate, polycarbonate diol and dimethylol propionic acid, with aminopropyl triethoxysilane (APS). Subsequently, silylated acrylic polyurethane dispersion was synthesized by reacting the PUD with the mixture of acrylate monomers, 2-hydroxyethyl methacrylate and methyl methacrylate. The average particle size of silylated acrylic polyurethane dispersion, measured by the dynamic light scattering method, was increased from 39.0 nm to 399.8 nm by increasing the addition amounts of APS. Also, the pencil hardness of coating films of silylated acrylic polyurethane dispersion was enhanced from B grade to F grade with increasing APS content.

• Korean Chemical Engineering Research
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• v.49 no.5
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• pp.548-553
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• 2011

NCO terminated polyurethane prepolymers were synthesized from isophorone diisocyanate(IPDI), polycarbonate diol(PCD) and dimethylol propionic acid(DMPA). Subsequently, acrylic terminated polyurethanes were prepared by capping the NCO groups of polyurethane prepolymers with different types of acrylate monomers, such as 2-hydroxyethyl methacrylate(HEMA), 2-hydroxyethyl acrylate(HEA) and pentaerythritol triacrylate(PETA). The average particle sizes of the acrylic terminated polyurethane solutions were increased by capping acrylate monomers. Also, the prepared coating films showed better abrasion resistance and pencil hardness than those of pure waterborne polyurethanes. The coating film with PETA exhibited the best abrasion resistance and pencil hardness of coating films prepared with three acrylate monomers.

• Korean Chemical Engineering Research
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• v.54 no.3
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• pp.387-393
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• 2016

Fluorinated polyurethane coating solutions were synthesized from perfluoroalkyl alcohol, toluene diisocyanate, and polycarbonate diol as starting materials. Next, coating films were prepared by spin-coating the fluorinated polyurethane coating solutions on the PC substrates, followed by thermal curing at $120^{\circ}C$. The obtained fluorinated polyurethane coating films were characterized by FT-IR spectroscopy, UV-Vis spectrometer, contact angle tester and pencil hardness tester. Contact angle measurements of water on the coating films showed that the addition of perfluoroalkyl alcohol improved the water repellency and increased the contact angle from $81^{\circ}C$ to $111^{\circ}C$. However, the pencil hardness of coating films exhibited a constant grade of H, irrespective of the addition of perfluoroalkyl alcohol.

• 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).

• Korean Chemical Engineering Research
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• v.50 no.2
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• pp.191-197
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• 2012

Acrylic terminated polyurethane prepolymers were synthesized by capping the NCO groups of polyurethane prepolymers, prepared from isophorone diisocyanate (IPDI), polycarbonate diol (PCD) and dimethylol propionic acid (DMPA), with pentaerythritol triacrylate (PETA). Subsequently, silylated acrylic terminated prepolymers were prepared by capping the NCO groups of acrylic terminated polyurethane prepolymers with different types of silane coupling agents, glycidoxypropyl trimethoxysilane (GPTMS) or aminopropyl triethoxysilane (APS). The average particle size of pure waterborne polyurethane solution, measured by the dynamic light scattering method, was increased from 14.3 nm to 208.6 nm by adding PETA and APS. Also, the coating film of silylated acrylic terminated waterborne polyurethane showed better abrasion resistance and pencil hardness than that of pure waterborne polyurethane.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.410-416
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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, polyurethane-acrylic hybrid solutions were prepared by reacting the PUD with different types of acrylate monomers, such as HEMA (2-hydroxyethyl methacrylate):MMA (methyl methacrylate), HEMA:BA (butylacrylate), HEMA:BMA (butyl methacrylate), HEMA:HEA (2-hydroxyethyl acrylate), HEMA:PETA (pentaerytritol triacrylate) mixture. Also, the effects of acrylate types on the chemical resistance and the abrasion resistance of polyurethane-acrylic hybrid solutions were investigated. The test results showed that the HEMA:MMA mixture had the strongest chemical resistance, while the HEMA:PETA mixture had the strongest abrasion resistance among several types of acrylate mixtures.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.403-409
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• 2012

Polyurethane prepolymers were prepared from poly (carbonate diol), isophrone diisocyanate, and dimethylol propionic acid. Then, aniline terminated waterborne polyurethane dispersion (ATWPUD) was synthesized by capping aniline on the NCO group of the prepolymer. Subsequently, ATWPUD was mixed with multi-walled carbon nanotube (MWCNT) to yield coating solutions, and the mixture was coated on the polycarbonate substrate. The surface resistance ($10^{7.6}{\sim}10^{7.7}{\Omega}/cm^2$) of coating films from ATWPUD showed better conducting properties than that ($10^{10.9}{\Omega}/cm^2$) from pure waterborne polyurethane dispersion (WPUD) when MWCNT was mixed. Also, the surface resistance of coating films was increased, but the pencil hardness and adhesion were decreased with increasing the amount of MWCNT added in the ATWPUD.