• Elastomers and Composites
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• v.57 no.1
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• pp.13-19
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• 2022

Polycarbonate diol-based waterborne polyurethane (WPU) was prepared by prepolymer mixing process. The prepolymer mixture contained the polycarbonate diol, isophorone diisocyanate (IPDI), dimethylol propionic acid, triethylamine, and ethylenediamine (EDA). The NCO/OH ratio in the prepolymer was adjusted by controlling the molar ratio of IPDI, and its effects on the properties of WPU were studied. The structure of WPU was characterized by fourier transform infrared spectroscopy. The average particle size increased and viscosity decreased with increasing NCO/OH ratio and EDA content in WPU. The reduced phase separation between soft and hard segments increased glass transition temperature. The reduction in the thermal decomposition temperature could be attributed to the low bond energy of urethane and urea groups, which constituted the hard segment. Additionally, the polyurethane chain mobility was restricted, elongation decreased, and tensile strength increased. The hydrogen bond between the hard segments formed a dense structure that hindered water absorption.

• Elastomers and Composites
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• v.55 no.1
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• pp.20-25
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• 2020

The effect of the isocyanate index (NCO index) on the particle size and particle size distribution of a waterborne polyurethane dispersion (WPUD) with polycarbonate-diol was determined. The WPUDs were prepared using a conventional acetone process with polycarbonate-polyol (M_n = 2028), 4,4'-methylenebis(cyclohexyl isocyanate) (H₁₂MDI), 2,2-bis(hydroxymethyl) propionic acid (DMPA), and dibutyltin dilaurate catalyst. At NCO index values below 1.5, the number average particle diameter of the WPUDs significantly increased with the NCO index, whereas the particle diameter slightly varied at higher NCO indexes. The dependency of the WPUD viscosity on the NCO index exhibited similar behavior to that of the particle size. The relative values of the full width at half maximum of the WPUD particle distribution curves at various NCO indexes were not influenced by the NCO index.

• Journal of Adhesion and Interface
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• v.12 no.4
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• pp.105-110
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• 2011

Polyester/melamine cured coatings had been used for pre-primed coatings and pre-coated metal coatings, because it has good mechanical,chemical properties, and mar resistance. But it has weak points such as stiffness and low formability for making automotive components. Polyester had been synthesized using polycarbonate diol of long alkyl chain which can improve flexibility and formability which is one of the important factors for pre-coated steel sheets (PCM). In this study, strain and tensile strength were examined by the tensile test and formability was examined by the drawing test. Also, Those polyester resins were also measured by DMA to verify flexibility of cured coatings.

• Polymer(Korea)
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• v.33 no.2
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• pp.175-182
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• 2009

Waterborne polyurethanes (WPUs) based on isophorone diisocyanate and mixed polyols of poly(tetramethylene glycol) (PTMG)/polycarbonate diol (PCD) were synthesized. The variation of mechanical and dyeing properties and alkali resistance of the WPU films were analyzed according to the polycarbonate (PC) content. The tensile strength of the films increased and the elongation at break decreased with the PC content in the WPU film. The incorporation of PC component in the WPU film did not affect the alkaline hydrolysis behavior. The synthesized WPU solutions were used as impregnating resins for the production of PET artificial leathers. The prepared WPU resins showed the good color fastness to washing, rubbing, and light of the artificial leather fabrics. The improvement of the properties became greater with the PC content in the WPU resin.

• Korean Chemical Engineering Research
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• v.48 no.2
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• pp.164-171
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• 2010

Recently, the waste of Polycarbonate(PC) is increase with the increase in demand of a polycarbonate. It is concerned with producing a new material and diol monomer, bishydroxyethyl ether of bisphenol A(BHE-BPA) through depolymerization of the polycarbonate waste at recycling. BHE-BPA can be used as a good raw material for the synthesis of polycarbonate type polyurethane. PC particles were depolymerized with base-catalyst NaOH, solvent EG, and ethylene carbonate(EC) was formed during the PC depolymerziation. EC was added to promote the conversion from bispenol-A to BHE-BPA. The characteristics of depolymeraion of polycarbonate as well as conversion of bispenol-A to BHE-BPA were investigated. BHE-BPA yield of 92% was obtained at temperature $220^{\circ}C$, 10% catalyst/PC mole ratio, 20 mmol of EC. BHE-BPA purity of better than 99% was achieved by crystallization of BHE-BPA.

• Journal of Adhesion and Interface
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• v.12 no.2
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• pp.47-55
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• 2011

UV-curable coatings have been used in various industries due to their advantages such as high mechanical property, good solvent resistance, fast curing process and low volatile organic compounds. However, a lack of flexibility of UV-cured films is a weak point for the pre-coated system of roll-to-roll process. In this study, UV-curable polycarbonate-based methacrylates were synthesized with polycarbonate diol, isophorone diisocyanate and 2-hydroxyethylmethacrylate to improve flexibility of the UC-cured films. The effects of polyol molecular weight, content of photoinitiator and monomers on the UV-curing behavior, flexibility and properties were investigated. The UV-curing behavior was measured by a photo-DSC, the pendulum hardness, tensile strength, viscoelastic properties were also evaluated.

• Korean Chemical Engineering Research
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• v.52 no.4
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• pp.451-458
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• 2014

Waterborne polyurethane dispersion (WPUD) was prepared from polycarbonate diol (PCD), isophorone diisocyanate (IPDI) and dimethylol propionic acid (DMPA) as starting materials. Then, waterborne acrylic polyurethane dispersion (AUD) was synthesized by reacting the WPUD with different types of acrylate monomers, such as methyl methacrylate (MMA), 2-hydroxyethyl methacrylate (HEMA) and butyl acrylate (BA). Subsequently, the AUD was mixed with multi-walled carbon nanotube (MWCNT) to yield a conductive coating solution, and the mixture was coated on the polycarbonate substrate. The pencil hardness, abrasion resistance and chemical resistance of the coating films from AUD were improved than those from WPUD, while the electrical conductivity of the coating films from AUD was decreased than that of WPUD. Also, the effect of acrylate types on the properties of coating films was investigated. The AUD obtained from HEMA showed the strongest pencil hardness, while the AUD obtained from MMA exhibited the strongest abrasion resistance, chemical resistance and electrical conductivity among several types of acrylate monomers.

• Korean Chemical Engineering Research
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• v.51 no.1
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• pp.73-79
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• 2013

Waterborne polyurethane dispersion (WPUD) was synthesized from polycarbonate diol (PCD), isophorone diisocyanate (IPDI) and dimethylol propionic acid (DMPA) as starting materials. Then, waterborne acrylic polyurethane dispersion (AUD) was synthesized by reacting the WPUD with an acrylate monomer, methyl methacrylate (MMA). Subsequently, the AUD was mixed with multi-walled carbon nanotube (MWCNT) to yield a conductive coating solution, and the mixture was coated on the polycarbonate substrate. With increasing the amount of MMA in the AUD, the pencil hardness, abrasion resistance and chemical resistance of the coating films were improved, but the electrical conductivity of the coating films was decreased. On the other hand, the pencil hardness, abrasion resistance and chemical resistance of coating films were decreased, but the electrical conductivity was enhanced with increasing the amount of MWCNT in the conductive coating solutions.

• Korean Chemical Engineering Research
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• v.49 no.4
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• pp.411-416
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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 prepolymers were prepared by capping the NCO groups of polyurethane prepolymers with different moles of pentaerythritol triacrylate (0~0.024 moles) as a acrylate monomer. The average particle size of the acrylic terminated polyurethane solutions was increased with increasing PETA contents. Also, the prepared coating films showed better abrasion resistance and pencil hardness than pure waterborne polyurethane.

• Polymer(Korea)
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• v.34 no.6
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• pp.507-510
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• 2010

Poly(cyclohexane carbonate) diol was synthesized by the alternating copolymerization of cyclohexene oxide and $CO_2$ over Cr based transition metal catalysts. The prepared PCCD was applied as a precursor for the preparation of waterborne polyurethane (PUD) in order to investigate an application field of carbon dioxide-based polycarbonate. The scratch resistance and thermal properties of PUDs, which was prepared with two kinds of polymeric diols (PCD and PCCD) were investigated. The scratch resistance and thermal decomposition temperature of PUD film prepared with PCCD is worse than those prepared with PCD, poly(hexamethylene carbonate) glycol. While, glass transition temperature of PUD film prepared with PCCD was higher than that prepared with PCD. It might be due to the rigid cyclohexane structure in the PCCD.