• Applied Chemistry for Engineering
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• v.19 no.4
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• pp.427-431
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• 2008

The rigid polyurethane foams (PUF) were prepared using polyols with 90, 110, 130, and 150 isocyanate index. The effect of sea water on the physical properties of PUF with the increase in isocyanate (NCO) index and ageing time was investigated. Tensile strengths and compressive strengths of the PUFs decreased up to 10% and 7% with an increase in ageing time, respectively. Cell morphology of the PUF under sea water was turned out to be the same as that in the ambient condition. It was observed that $T_g$ and tensile modulus of the PUF under sea water increased. The results showed an additional cross-link reaction of non-reacted MDI and the change of NCO peak as observed from FT-IR spectrum.

• Journal of Adhesion and Interface
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• v.15 no.4
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• pp.151-160
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• 2014

A series of terpolymers based on stearyl methacrylate (SMA), n-methyol acrylamide (n-MAM), and 2-(perfluorooctyl) ethyl acrylate (PFOEA) were synthesized by changing PFOEA contents up to 8 wt% in order to obtain optimal water-repellent properties. In addition, various contents of m-isopropenyl-${\alpha}$,${\alpha}^{\prime}$-dimethylbenzyl isocyanate (TMI) from 1 to 4 wt% were added to the above terpolymers with 4 wt% of PFOEA content. The emulsion polymerization was carried out using tridecyl alcohol (EO)7 (TDA-7) as a nonionic surfactant, alkyl dimethyl amine derivatives (ADAD) as a cationic surfactant, and 2,2'-azobis(2-amidinopropane dihydrochoride) (AAPDL) as an initiator. The synthesized copolymers were characterized by FT-IR spectroscopies, contact angle, surface energy, and water-repellency. Surface and thermal properties were analyzed by SEM, TGA, and DSC. It was found that water repellency increased with increasing the contents of PFOEA and TMI.

• Journal of Adhesion and Interface
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• v.14 no.1
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• pp.43-48
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• 2013

The physical properties of the acrylic pressure sensitive adhesives (PSAs) can be easily controlled by a proper functional monomer which has functional groups for crosslinking. This study was to investigate the effect of crosslinking agents, isocyanate and epoxy types, of acrylic PSAs on adhesive properties. 2-Ethylhexyl acrylate, acrylic acid (AA), and 2-hydroxy ethyl methacrylate as monomer were used. The obtained samples with different AA contents were partially crosslinked with epoxy- or isocyanate-typed agent. Peel strength, balltack, holding power test and contraction percentage of the obtained PSA were evaluated. Most properties of acrylic PSAs were increased with AA content and acrylic PSAs with epoxy-typed crosslinking agent (4 crosslinking sites) which produces flexible link (ether), showed better properties than those of isocyanate-typed one (3 crosslinking sites).

• Journal of the Korean Applied Science and Technology
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• v.30 no.3
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• pp.551-559
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• 2013

To investigate the adhesion effect of sodium bisulfite content in making blocked isocyanate, wood adhesive PB-1, PB-2, PB-3 and PB-4 containing sodium bisulfite content of 15%, 22.5%, 30% and 37.5% were synthesized respectively. As a result, when the amount of sodium bisulfite increased in adhesives, the tensile strength was found to be proportionally increased. The final adhesive mixtures were manufactured using a two-components system which are prepared by mixing two separate protein and BI solutions due to the precipitate in the adhesives. As PVA was added to adhesives to increase tenacity, the plywood dehiscence phenomenon after cold pressing process was declined. By addition of PVA, the tensile strength was improved up to $6.5{\sim}7kgf/cm^2$ with BI/protein ratio from 1:6 up to 1:8. Phase separation between milk fat and aqueous layer was disappeared after addition of emulsifier, Tween 20. Additon of Tween 20 showed tensile strength up to $5{\sim}6.5 kgf/cm^2$ at NCO/protein ratio of 1:12 ~ 1:14 without phase separation.

• Bulletin of the Korean Chemical Society
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• v.19 no.11
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• pp.1211-1216
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• 1998

Bis(diethyldithiocarbamato)ioxomolybdenum(VI), cis-MoO2(S2CNEt2)2, 1, reacted with chlorotrimethylsilane (Me33SiCl) to give a seven-coordinate, pentagonal bipyramidal complex MoOC12(S2CN]Et2)2, 3, in which the oxo ligand is trans to the chloride ligand and the two chloride ligands are mutually cis. The monooxo molybdenum complex bis(diethyidithiocarbamato)oxomolybdenum(IV), MoO(S2CNEt2)2, 2, reacted with phenyl isocyanate (PhNCO) to give an Mo dimer MO2{μ-N(CONPh)Ph}(μ-NPh)(NPh)2(S2CNEt2)2, 4, which contains an Mo-Mo bond, two diethyldithiocarbamato ligands, two terminal imido (NPh) ligands, and two bridging hnido (NPh) ligands. One of the two bridging NPh ligands seemed to have been attacked by the electrophilic phenyl isocyanate carbon, which suggests that the bridging imido NPh ligand is more nucleophilic than the terminal one. Crystallographic data for 3: monoclinic space group P21/c, a=8.908(l) Å, b=17.509(3) Å, c=12.683(2) Å, β=110.15(1)°, Z=4, R(wR2)=0.0611(0.1385). Crystallographic data for 4-THF: orthorhombic space group P212121, a=17.932(4) Å, b=22.715(5) Å, c=11.802(3) Å, Z=4, R(wR2)=0.0585(0.1286).

• Applied Chemistry for Engineering
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• v.24 no.2
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• pp.148-154
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• 2013

UV curable acryl resin, pressure-sensitive adhesives (PSAs), are used in many different parts in the world. In particular, PSAs has been used in the wafer manufacturing process of semiconductor industry. As wafers become much thinner, UV curable PSAs require more proper adhesion performance. In this study, acrylic PSAs containing hydroxyl groups were synthesized using monomers of 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, styrene monomer and 2-hydroxyethyl acrylate. Isocyanate modified UV curable PSAs were then prepared by the adduct reaction that facilitates the UV curing property via controlling the amount of methacryloyloxyehtyl isocyanate. The proper adhesion performance and UV curing behavior of UV curable PSAs with various hydroxyl values were studied, and experimental conditions were then optimized to raise the efficiency of wafer manufacturing process. It was found that in case of using the equivalent ratio of 1 : 1 isocyanate hardener used in the UV curable PSAs, the peel strength before the UV curing process decreased as the amount of hydroxyl groups increased in the PSAs. The peeling adhesive strength was also decreased with increasing UV dose due to high curing characteristics.

• Journal of the Korean Wood Science and Technology
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• v.23 no.2
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• pp.70-76
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• 1995

Research was conducted at the Wood Materials and Engineering Laboratory, Washington State University, Pullman, WA to evaluate the effects of the sequence of wax addition, wax level, and wax type on mechanical properties and water resistance performance of isocyanate-bonded particleboard. Mechanical properties and water resistance performance were not influenced significantly by the sequence of wax addition. Internal bond and wet modulus of rupture in bending strength were decreased significantly by increasing the wax emulsion level, but dry modulus of rupture and modulus of elasticity in bending strength were not decreased significantly by increasing the wax emulsion level. Dry internal bond, dry and wet moduli of rupture, and modulus of elasticity were not decreased by increasing the solid wax level except for wet internal bond. The addition of 1.0 and 1.5% wax level did not produce any significant additional water resistance effect when compared to the addition of 0.5% wax level. Internal bond values of boards with solid wax addition showed significantly better results than boards with just a wax emulsion added. Modulus of rupture, modulus of elasticity, and water resistance performance did not show significant difference between solid wax and wax emulsion.

• Proceedings of the Korean Fiber Society Conference
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• 1999.04a
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• pp.53-56
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• 1999

• 월간산업보건
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• s.102
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• pp.43-48
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• 1996

최근 Isocyanate의 일종으로 Hexamethylene diisocyanate(HDI)가 사용되고, 주로 자동차의 도장공을 중심으로 천식이나 과민성 폐장염의 보고가 증가하고 있다. 과거 20년에 걸친 주된 문헌을 요약해 보았다.

• 월간산업보건
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• s.122
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• pp.45-49
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• 1998