• Macromolecular Research
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• v.14 no.6
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• pp.634-639
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• 2006

Waterborne polyurethane (WBPU) adhesive with varying amounts of dimethylol propionic acid (DMPA) was synthesized by prepolymer process and blended with polyisocyanate hardener. The mean particle size of the WBPU dispersion decreased with increasing DMPA content. $^1H$ NMR spectroscopy confirmed the formation of allophanate bonds and biuret bonds due to the reaction of hardener NCO with urethane/urea groups. The optimum NCO content with the greatest adhesive strength was dependent on the total content of urethane/urea groups in the WBPU molecules. The optimum NCO content increased with increasing number of urethane groups (DMPA content). The adhesion strength of WBPU adhesives was maximized at a molar ratio of hardener NCO to urethane/urea of about 0.28.

• Polymer(Korea)
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• v.35 no.6
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• pp.553-557
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• 2011

Poly(vinyl alcohol) (PVA)/waterborne polyurethane (WBPU)/montmorillonite clay (MMT) nanocomposite nanofibers were prepared using electrospinning technique of aqueous solutions. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction and thermal gravimetric analyzer were used to characterize the morphology and properties of the nanocomposite nanofibers. Since PVA, WBPU and MMT are hydrophilic, non-toxic and biocompatible materials, these nanocomposite nanofibers can be used for filter and medical industries as wound dressing materials, antimicrobial filters, etc.

• Macromolecular Research
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• v.15 no.1
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• pp.22-30
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• 2007

High water vapor permeable coating materials were prepared by blending aqueous poly(vinyl alcohol) (PVA) solution with waterborne polyurethane-urea (WBPU) dispersions synthesized by prepolymer mixing process. Stable WBPU/PVA dispersions were achieved at PVA content below 30 wt%. As the water soluble polymer PVA content increased, the number and density of total micro-pores (tunnel-like/isolated micro-pores) formed after the dissolution of PVA in water increased, and the water vapor permeability of coated Nylon fabric also increased significantly. Using WBPU/water soluble polymer PVA blends as a coating material and then dissolving PVA in water was confirmed to be an effective method to obtain prominent breathable fabrics.

• Journal of Environmental Science International
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• v.21 no.4
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• pp.507-515
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• 2012

To improve the mechanical properties of hydroxyapatite (HA)/waterborne polyurethane (WBPU) composites, the hydroxyl group of HA was modified by urethane reactions: the hydroxyl groups of HA were reacted with aliphatic or cyclic diisocyanate, and then the modified HAs were extended by adding polyol and/or ${\varepsilon}$-caprolactone. Composites were prepared by the prepolymer process method: the modified HA was directly pured into the urethane reaction of isocyanate and polyol. The properties of modified HA/WBPU composites were investigated by thermogravimetric analysis, tensile strength, and water resistance. The results showed that the reactivity of aliphatic diisocyanate to the hydroxy group of HA was faster than that of cyclic one. Comparing to those of pure HA/WBPU composite films, the thermal stability, water resistance, and mechanical properties of the modified composite films increased with a degree of modification of HA.

• Macromolecular Research
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• v.12 no.3
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• pp.303-310
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• 2004

We have prepared an aqueous dispersion of poly(aniline-dodecyl benzene sulfonic acid complex) (PANI-DC) that has an intrinsic viscosity (〔η〕) near 1.3 dL/g using aniline as a monomer, dodecyl benzene sulfonic acid(DBSA) as a dopant/emulsifier, and ammonium peroxodisulfate(APS) as an oxidant. We found that the electrical conductivity of a PANI-DC pellet was 0.7 S/cm. A waterborne-polyurethane (WBPU) dispersion, obtained from isophorone diisocyanate/polytetramethylene oxide glycol/dimethylol propionic acid/ethylene diamine/triethylene amine, was used as a matrix polymer. We prepared blend films of WBPU/PANI-DC with variable weight ratios (from 99/1 to 66/34) by solution blending/casting and investigated the effects that the PANI-DC content has on the mechanical and dynamic mechanical properties, hardness, electrical conductivity, and antistaticity of these films. The tensile strength, percentage of elongation, and hardness of WBPU/PANI-DC blend films all decreased markedly upon increasing the PANI-DC content. The antistatic half-life time ($\tau$$\sub$$\frac{1}{2}$/) of pure WBPU film was about 110 s, but we found that those of WBPU/ultrasound-treated PANI-DC blend films decreased exponentially from 1.2 s to 0.1 s to almost 0 s upon increasing the PANI-DC content from 1 wt% to 15 wt% to > 15 wt%, respectively.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.38-41
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• 2003

Recently, Waterhorne polyurethane(WBPU) have been used for a wide range of commercial applications due to the increasing environmental regulation to reduce low-volatile organic compounds in coating and adhesives materials [1-8]. The WBPU was used in coating industry on fiber at first, and its market is increasing these days. Especially, the Waterborne polyurethane film even is widely used in the field of breathable coating fiber or medical science [9-10]. Water vapor permeability(WVP) is the key property for application to breathable coating fiber. (omitted)

• 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.

• Fibers and Polymers
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• v.7 no.2
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• pp.95-104
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• 2006

In order to improve the water swelling, thermal/mechanical and adhesion properties of waterborne polyurethane (WBPU), a series of the crosslinkable WBPUs containing hydrophilic ionic component, dimethylol propionic acid (20 mole%), were prepared by in-situ polymerization using a cross-linker hexakis (methoxymethyl) melamine (HMMM). Effects of the HMMM content (2, 4, and 6 wt%) and curing temperature on these properties of the crosslinked WBPUs samples were investigated. All properties were found to increase with increasing HMMM content. It was found that the optimum curing temperature of the WBPU films and adhesives was near $120^{\circ}C$, which was not dependent on the HMMM content.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.42-45
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• 2003

Polyurethane(PU) products are generally used in the automobile, paint, furniture, adhesive, the medical and textile industries. Recently, the increasing acceptance of waterborne polyurethane (WBPU) Is motivated by more stringent environmental requirements, such as the reduction of solvent emissions into the atmosphere [1]. The application for textiles includes suede processing, soft-hand processing, wrinkle-free processing, antistatic processing, sizing and adhesives. (omitted)

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.287-288
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• 2003

Polyurethane(PU) materials have been generally used in the automobile, paint, furniture, adhesive, and textile industries. The use of Waterborne PU was motivated form the environmental point of view, i.e. reduction of solvent emissions into the atmosphere(volatile organic compounds, VOC)[1]. Generally speaking, phase change materials (PCM) have the capability of absorbing or releasing thermal energy to reduce or eliminate heat transfer at the temperature range of the particular temperature stabilizing material[2]. (omitted)