• 청정기술
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• 제23권2호
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• pp.148-157
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• 2017

To prepare UV-curable polyurethane-acrylate oligomer, NCO-terminated urethane prepolymers with trimethylolpropane, [TMP; 0 (0), 0.1 (0.021) and 0.2 (0.043) mole (mole fraction)] as crosslinkable tri-functional chain extender were end-capped with pentaerythritol triacrylate [PETA; 2.0 (0.400), 1.7 (0.354) and 1.4 (0.304) mole (mole fraction)] with one hydroxyl group/three vinyl functionalities. The stable as-formulated UV-curable polyurethane-acrylates [stable mixtures of PETA-capped oligomer/reactive acrylic monomer diluents without/with heptadecafluorodecyl methacrylate (PFA; 0, 6 and 9 wt%)] were formed up to 0.2 (0.043) mole (mole fraction) of TMP content in the prepolymer, while homogeneous-mixing failed at 0.3 (0.068) mole (mole fraction), in which the crosslink density in NCO-terminated urethane prepolymer was too high to enable the formation of stable mixture. This study examined the effect of TMP/PETA molar ratio and heptadecafluorodecyl methacrylate (PFA) content (wt%) on the properties of UV-cured polyurethane-acrylates as marine antifouling coating materials. The properties of UV-cured polyurethane-acrylate were found to be significantly dependent on the crosslinkable TMP/PETA ratio and PFA content. With the increasing of the TMP and PFA contents, the contact angles increased, and consequently the surface tension decreased. The adhesion of algae/barnacles to PFA contained film samples were found to be sufficiently weak to allow their easy removal. These results suggest that the UV-cured samples containing PFA have strong potential as coating materials for antifouling applications.

• 한국응용과학기술학회지
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• 제23권1호
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• pp.85-91
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• 2006

Acrylic resins (HSCs : EA/EMA/2-HEMA/CLA) which contain 80% solid content were synthesized by the copolymerization of monomers (ethyl acrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate) and functional monomer (caprolactone acrylate : CLA) which improves the crosslinking density and physical properties of films. The physical properties of the prepared acrylic resins (HSCs) containing CLA, are as follows: viscosity 1440$^{\sim}$2630 cps ; $M_n$ 1590$^{\sim}$1660 ; and conversions, 81$^{\sim}$86%, respectively. From the correlation of $T_g$ values, viscosities, and $M_n$ of the HSCs, it was found thst viscosity and $M_n$ increased with $T_g$ value.

• 한국응용과학기술학회지
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• 제21권3호
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• pp.197-203
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• 2004

Acrylic resins ($HSC_s$ : EA/EMA/2-HEMA/CLA) which contain 70% solid content were synthesized by the copolymerization of monomers (2-hydroxyethyl methacrylate, ethyl acrylate, and ethyl methacrylate) and functional monomer (caprolactone acrylate : CLA) which improves the crosslinking density and physical properties of films. The physical properties of the prepared acrylic resins (HSCs) containing CLA, are as follows : viscosity 245${\sim}$515 cps ; $M_n$ 2670${\sim}$2840 ; and conversions, 83${\sim}$91%, respectively. From the correlation of $T_g$ values, viscosities, and $M_n$ of the HSCs, it was found that viscosity and $M_n$ increased with $T_g$ value.

• Korean Chemical Engineering Research
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• 제47권4호
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• pp.470-475
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• 2009

본 연구에서는 유화중합을 이용한 수분산성 아크릴계접착제의 최적의 합성조건을 구하기 위하여 주단량체로 2-EHA(2-ethylhexyl acrylate), n-BA(n-butyl acrylate), MMA(methyl metacrylate), 기능성단량체로 2-HEMA(2-hydroxylethylmethacrylate), AAc(acrylic acid), 유화제로는 음이온성 유화제인 SLS(Sodium Lauryl Sulfate), 그리고 개시제로 APS(Ammonium persulfate)를 사용하여 전환율, 입자 크기, 박리강도, 유리전이온도에 대한 유화제, 개시제, 단량체 함량의 영향을 고찰하였다. 반응온도 $82^{\circ}C$, 유화제(SLS/monomer) 3.75%, 개시제(APS/monomer) 0.612%에서 95% 이상의 전환율을 얻을 수 있었고, 유화제나 개시제의 양이 너무 많을 때는 박리접착강도가 감소하는 경향을 보였으며, 65% 2-EHA/monomer, 20% BA/monomer, 10% MMA/monomer에서 최대 전환율과 최대 박리접착강도를 얻을 수 있었다.

• 접착 및 계면
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• 제14권1호
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• pp.43-48
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• 2013

압력감응성 아크릴 점착제의 물성은 가교를 위한 관능성그룹을 가진 단량체를 이용하여 쉽게 물성을 조절할 수 있다. 본 연구에서는 두개의 다른 가교제, isocyanate 및 epoxy형 가교제에 따른 아크릴 점착제의 가교특성과 물성을 연구하였다. 2-Ethylhexyl acrylate, acrylic acid (AA)와 2-hydroxyethyl methacrylate를 주 단량체로 하여 이소시아네이트 또는 에폭시형 가교제로 가교한 점착제의 박리점착 특성, 볼텍, 유지력 및 수축성을 고찰하였다. 점착특성은 AA함량 증가와 더불어 증가하였고 가교점이 많고 ether와 같은 유연한 결합을 생성하는 에폭시형 가교제에서 우수한 물성을 나타내었다.

• Corrosion Science and Technology
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• 제14권5호
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• pp.213-217
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• 2015

Recently, household electronic industries require environmentally-friendly and highly functional steels in order to enhance the quality of human life. Customers especially require both excellent corrosion and abrasion resistant anti-fingerprint steels for digital TV panels. Thus POSCO has developed new functional electro-galvanized steels, which have double coated layers with organic-inorganic composites on the zinc surface of the steel for usage as the bottom chassis panel of TVs. The inorganic solution for the bottom layer consists of inorganic phosphate, magnesium, and zirconium compounds with a small amount of epoxy binder, and affords both improved adhesion properties by chemical conversion reactions and corrosion resistance due to a self-healing effect. The composite solution for the top layer was prepared by fine dispersion of organic-inorganic ingredients that consist of a urethane modified polyacrylate polymer, hardener, silica sol and a titanium complex inhibitor in aqueous media. Both composite solutions were coated on the steel surface by using a roll coater and then cured through an induction furnace in the electro-galvanizing line. New anti-fingerprint steel was evaluated for quality performance through such procedures as the salt spray test for corrosion resistance, tribological test for abrasion resistance, and conductivity test for surface electric conductance regarding to both types of polymer resin and coating weight of composite solution. New composite coated anti-fingerprint steels afford both better corrosion resistance and abrasion properties compared to conventional anti-fingerprint steel that mainly consists of acrylate polymers. Detailed discussions of both composite solutions and experimental results suggest that urethane modifications of acrylate polymers of composite solutions play a key role in enhanced quality performances.

• 전기화학회지
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• 제16권3호
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• pp.177-183
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• 2013

고전압에서도 사용 가능한 바인더 개발에 대한 요구가 증대됨에 따라 이에 적합한 내산화성이 우수한 바인더를 양자화학적 모델링에 기반하여 제안하고자 하였다. 각 고분자 poly(acryl amide)(PAM), poly(methyl acrylate)(PMA), poly(vinylidene fluoride)(PVDF), poly(hexafluropropylene)(PHFP)에 대하여 반경험적 방법(Semi-empirical method) 및 밀도범함수 이론(Density Functional Theory, DFT) 방법을 이용하여 단량체부터 사량체까지의 고분자 바인더에 대한 최고 점유 분자 궤도함수(Highest occupied molecular orbital, HOMO) 에너지와 이온화 에너지(Ionization Potential, IP) 값을 구하여 실험 값과 비교하였다. 밀도범함수 방법으로 해석한 결과, PHFP, PVDF, PMA, PAM 순으로 고분자의 내산화성이 좋은 것으로 시뮬레이션을 통해 예측되었고, 이러한 결과는 선형 훑음 전압-전류법(Linear Sweep Voltametry, LSV)으로부터 얻은 실험값과 일치하였다. 또한 이 결과는 HOMO 오비탈의 구조를 분석하여 내산화성이 좋은 원인을 규명하였다.

• 폴리머
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• 제36권1호
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• pp.29-33
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• 2012

관능성 단량체로서 acrylic acid(AA)를 사용하였고, 기본 단량체로서는 2-ethylhexyl acrylate(2-EHA)를 사용하여 용액중합의 방법으로 점착제를 합성하였다. 점착제의 점착물성 중에 AA와 경화제 함량에 따른 점착제의 표면에너지와 물성변화 연구를 조사하였다. 합성된 점착제의 구조는 FTIR을 통하여 확인하였고 점도와 분자량은 Brookfield 점도계와 GPC를 사용하여 각각 측정하였다. 분자량과 점도는 AA가 6 wt%까지는 함량증가에 따라 증가하였으며 6 wt% 이상에서는 감소하였다. 이러한 경향은 표면에너지 역시 AA 함량증가에 따라 COOH 그룹에 의한 극성 강화로 표면에너지는 증가하였다. 반면, 점착력은 분자량과 반비례 관계를 보였으며 AA 함량과 경화제 함량 증가에 따라 감소하는 경향을 나타내었다.

• Bulletin of the Korean Chemical Society
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• 제35권5호
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• pp.1403-1408
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• 2014

The cycloaddition reactions of the N-heterocyclic carbene boryl azide with methyl acrylate, butenone, and hexafluoropropene have been investigated theoretically. Solvent effects on these reactions have been explored by calculation that included a polarizable continuum model (PCM) for the solvent (C6H6). The title reaction could produce 4- and 5-substituted 1,2,3-triazolines, respectively. The reaction systems have the higher chemical reactivity with the low barriers and could be favored. Yet the smaller differences have been found to occur in energetics, and the cycloaddition reactions occur for s-trans conformations over s-cis conformations. The calculations indicated that the cycloaddition reaction of the alkenes have certain regioselectivity.

• 한국재료학회지
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• 제30권6호
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• pp.273-278
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• 2020

This research is conducted to analyze the compatibility of used monomers and produce the high functional hydrogel ophthalmic polymer containing silane and nanoparticles. VTMS (vinyltrimethoxysilane), TAVS [Triacetoxy(vinyl)silane] and cobalt oxide nanoparticles are used as additives for the basic combination of SilM (silicone monomer), MMA (methyl methacrylate) and MA (methyl acrylate). Also, the materials are copolymerized with EGDMA (ethylene glycol dimethacrylate) as cross-linking agent, AIBN (thermal polymerization initiator) as the initiator. It is judged that the lenses of all combinations are optically excellent and thus have good compatibility. Measurement of the optical and physical characteristics of the manufactured hydrophilic ophthalmic polymer are different in each case. Especially for TAVS, the addition of cobalt oxide nanoparticles increases the oxygen permeability. These materials are considered to create synergy, so they can be used in functional hydrogel ophthalmic lenses.