• Journal of Adhesion and Interface
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• v.10 no.4
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• pp.191-198
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• 2009

UV-curable aliphatic epoxy acrylates were prepared by the reaction of glycerol diglycidyl ether (GDE) with 2-carboxyethyl acrylate (2-CEA) or 2-hydroxyethyl acrylate (2-HEA). The structures of the epoxy acrylates were characterized by FT-IR, $^1H$-NMR, and $^{13}C$-NMR and the yield was obtained by prep-LC. The UV- and the thermal-curing behaviors of the product were investigated using photo-DSC and DSC, respectively. The reactivity of 2-CEA was higher than 2-HEA and the yield of the product (GEA-C) which was prepared using 2-CEA was about 83%. The maximum UV-curing time ($T_{max}$) of the GEA-C contained non-reactive components and by-product was about 10 seconds. The GEA-C showed low color difference (${\Delta}E^*$), low viscosity, and good thermal stability - its value was 2.51, 192 cps, and $299^{\circ}C$ (at 5% weight loss), respectively. The activation energies ($E_a$) of thermal-curing reaction calculated from Kissinger and Ozawa-Flynn-Wall method were 91~92 kJ/mol.

• Membrane Journal
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• v.34 no.1
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• pp.70-78
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• 2024

A photo-crosslinked anion exchange membrane (AEM) based on quaternary-aminated polyacrylates was developed for reverse electrodialysis (RED). Although reverse electrodialysis is a clean and renewable energy generation system, the low power output and high membrane cost are serious obstacles to its commercialization. Cross-linked AEMs without any polymer supporters were fabricated through photo-crosslinking between polymer-typed acrylates with anion conducting groups, in particular, polymer-typed acrylates were synthesized based on engineering plastic with outstanding mechanical and chemical property. The fabricated membranes showed outstanding physical, chemical, and electrochemical properties. The area resistance of the fabricated membranes (CQAPPOA-20, CQAPPOA-35, and CQAPPOA-50) were ~50% lower than that of AMV (2.6 Ω cm²). Moreover, the transport number of CQAPPOA-35 wase comparable to that of AMV, despite the thin thickness (40 ㎛) of the fabricated membranes. The RED stack with the CQAPPOA-35 membrane provided an excellent maximum power density of 2.327 W m^-2 at a flow rate of 100 mL min^-1, which is 15% higher than that (2.026 W m^-2) of the RED stack with the AMV membrane. Considering easy fabrication process by UV photo-crosslinking and outstanding RED stack properties, the CQAPPOA-35 membrane is a promising candidate for REDs.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.1891-1896
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• 2010

Submicron-sized polymeric colloidal particles can self assemble into 3-dimensional (3D) opal structure which is a useful template for photonic crystal. Narrowly dispersed polymer microspheres can be synthesized by emulsion polymerization in water using water-soluble radical initiator. In this report, we demonstrate a facile and reproducible emulsion polymerization method to prepare various polymeric microspheres within 200 - 400 nm size ranges which can be utilized as colloidal photonic crystal template. By controlling the amount of monomer and surfactant, monodisperse polymer colloids of polystyrene (PS) and acrylates with various sizes were successfully prepared without complicated synthetic procedures. Such polymer colloids self-assembled into 3D opal structure exhibiting bright colors by reflection of visible light. The colloidal particles and the resulting opal structures were rigorously characterized, and the wavelength of the structural color from the colloidal crystal was confirmed to have quantitative relationship with the size of constituting colloidal particles as predicted by Bragg equation. The tunability of the structural color was achieved not only by varying the particle size but also by infiltration of the colloidal crystal with liquids having different refractive indices.

• Macromolecular Research
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• v.15 no.6
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• pp.533-540
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• 2007

We designed and successfully synthesized UV curable, functional acrylate monomers having a polarizing group, i.e., an electron-withdrawing and/or electron-donating group for the optical materials of high refractive index. Optical polymer films made from the functional methacrylate monomers were achieved with photo crosslinking under UV illumination. A monomer having amino and cyano groups (Dimer-CN) exhibited the highest refractive index ($n_{TE}$=1.595 at 850nm) among the studied methacrylate derivatives, due to the large polarizability of the dipolar monomer structures with electron-donating and withdrawing groups. By controlling the compositions of the functional acrylate monomer of copolymers, the refractive indices of the polymers were readily adjusted within a wide range of 1.498-1.595. The copolymers showed a high glass transition temperature $(T_g)$ and good thermal stability, which are desirable for optical applications. $T_g$ and $T_{10%}$ (10%-weight loss occurred) of the copolymers ranged from $120-140^{\circ}C$ and from $329-387^{\circ}C$, respectively.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2139-2152
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• 2007

Ruthenium complex-catalyzed reactions often require highly qualified tuning of reaction conditions with substrates to attain high yield and selectivity of the products. In this review, our strategies for achieving characteristic ruthenium complex-catalyzed co-oligomerization of different alkenes are disclosed: 1) The codimerization of 2-norbornenes with acrylic compounds by new ruthenium catalyst systems of RuCl3(tpy)/Zn [tpy = 2,2':6',2''-terpyridine] or [RuCl2(η6-C6H6)]2/Zn in alcohols, 2) A novel synthesis of 2-alkylidenetetrahydrofurans from dihydrofurans and acrylates by zerovalent ruthenium catalysts, such as Ru(η4-cod)(η6-cot) [cod = 1,5-cyclooctadiene, cot = 1,3,5-cyclooctatriene] and Ru(η6-cot)(η2-dmfm)2 [dmfm = dimethyl fumarate], 3) Regio- and stereoselective synthesis of enamides by Ru(η6-cot)(η2-dmfm)2-catalyzed codimerization of N-vinylamides with alkenes, and 4) Unusual head-to-head dimerization of styrenes and linear codimerization of styrenes with ethylene by Ru(η6-cot)(η2-dmfm)2 catalyst in the presence of primary alcohols.

• Journal of the Korean Applied Science and Technology
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• v.17 no.4
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• pp.262-266
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• 2000

Acrylic pressure sensitive adhesives of n-butyl acrylate, 2-ethyl acrylate, methyl acrylate, vinyl acetate, acrylic acid, acrylonitrile and 2-hydroxyethyl acrylate were synthesized and basic physical properties of pressure sensitive adhesives with increasing the contents of 2-hydroxyethyl acrylate were investigated. 2-Hydroxyethyl acrylates effects on glass transition temperature, viscosity, hardening time and peel strength. Glass transition temperature(Tg) decreased with increasing the contents of 2-hydroxyethyl acrylate. Viscosity and hardening time were increased with increasing the contents of 2-hydroxyethyl acrylate. On the other hands, peel strength increased with increasing the contents of 2-hydroxyethyl acrylate up to 6 wt% and the decreased at further higher contents of 2-hydroxyethyl acrylate. In peel test, interfacial failure was occured in 8 wt% and 10wt%.

• Analytical Science and Technology
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• v.15 no.4
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• pp.341-345
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• 2002

The extent of UV-curing photo-polymerization reaction was monitored by near-IR spectroscopic method. Acrylates containing quaternary ammonium salts and Darocur 1173 were used as reactive monomer and a photo initiator, respectively. The extent of photo-polymerization reaction was obtained from the conversion ratio of acrylate double bond calculated from the intensities of measured bands at 1615 nm and at 2105 nm. Near-IR spectroscopic methods can be an useful tool for the monitoring of the progress of photo-polymerization.

• Macromolecular Research
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• v.14 no.5
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• pp.517-523
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• 2006

The effects of particle content, size and shape on the thermal conductivity (k) and adhesion properties of thermally conductive, pressure-sensitive adhesives (PSAs) were investigated. The matrix resins were thermally crosslinkable, 2-ethylhexyl acrylic polyol and ultraviolet (UV)-curable, random copolymer consisting of acrylic oligomer and various acrylates. We found that k increased with increasing diameter and particle aspect ratio, and was further enhanced due to the reduction of the interfacial thermal barrier when the coupling agent, which increases the adhesion between particles and the matrix resin, was used. On the other hand, adhesion properties such as peel strength and tack of the thermally crosslinkable resin decreased sharply with increasing particle content. However, for UV curable resin, increased particle addition inhibited the decrease in adhesion properties.

• Journal of Adhesion and Interface
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• v.18 no.4
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• pp.159-165
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• 2017

In this study, we synthesized UV-curable urethane acrylates with different contents of BA, reactive diluent and characterized their physical properties such as thermal, mechanical properties, adhesive strength and flexibility resistance. From a result of DSC, Tg of polyol and acrylate resin were separated as the BA content increased more than 40%. Also, tensile strength, elongation and adhesive strength decreased with increasing the BA content. The UV-curable urethane acrylate with 40% BA has shown good flexibility resistance compared to other resin due to poor hardness and Tm of acrylate resin.

• Macromolecular Research
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• v.16 no.7
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• pp.614-619
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• 2008

Copolymers of phenyl alkyl acrylates/methacrylates are used clinically as soft materials for the foldable intraocular lens (IOL) to treat cataracts. In this study, copolymers of 2-phenylethyl acrylate (PEA) and 2-phenylethyl methacrylate (PEMA) of various compositions were prepared using free radical polymerization in solution. The composition of the copolymers was determined by $^1H$-NMR analysis. The reactivity ratios of the monomers were calculated using the conventional Fineman-Ross or Kelen-Tudos method. The reactivity ratio of PEA ($r_1$) and PEMA ($r_2$) were estimated to be 0.280 and 2.085 using the Kelen-Tudos method, respectively. These values suggest that PEMA is more reactive in copolymerization than PEA, and the copolymers will have a higher content of PEMA units. The glass transition temperature ($T_g$) of the copolymers increased with increasing PEMA content. The molecular weight and polydispersity indices ($M_w/M_n$) of the polymers were determined by GPC. Overall, these results are expected to be quite useful in applications to foldable soft IOL materials.