• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.410-416
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• 2012

Waterborne polyurethane dispersions (PUD) were synthesized from isophorone diisocyanate (IPDI), polycarbonate diol (PCD) and dimethylol propionic acid (DMPA) as starting materials. Subsequently, polyurethane-acrylic hybrid solutions were prepared by reacting the PUD with different types of acrylate monomers, such as HEMA (2-hydroxyethyl methacrylate):MMA (methyl methacrylate), HEMA:BA (butylacrylate), HEMA:BMA (butyl methacrylate), HEMA:HEA (2-hydroxyethyl acrylate), HEMA:PETA (pentaerytritol triacrylate) mixture. Also, the effects of acrylate types on the chemical resistance and the abrasion resistance of polyurethane-acrylic hybrid solutions were investigated. The test results showed that the HEMA:MMA mixture had the strongest chemical resistance, while the HEMA:PETA mixture had the strongest abrasion resistance among several types of acrylate mixtures.

• Clean Technology
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• v.18 no.4
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• pp.366-372
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• 2012

Three acrylic copolymers containing tris(8-hydroxyquinoline) aluminum (AlQ3) pendant group (25 wt%), acrylateco-HEMA-$AlQ_3$ (25 wt%), were successfully synthesized by free radical polymerization from acrylates [methyl methacrylate (MMA), acrylonitrile (AN) or 2-hydroxyethyl methacrylate (HEMA)] with HEMA functionalized with AlQ3 pendant groups (HEMA-p-$AlQ_3$). The glass transition temperatures ($T_g$) of MMA-co-HEMA-p-$AlQ_3$ (copolymer 1), AN-co-HEMA-p-$AlQ_3$ (copolymer 2) and HEMA-co-HEMA-p-$AlQ_3$ (copolymer 3) were found to be 158, 150 and $126^{\circ}C$, respectively. They have good thermal stability: a very desirable feature for the stability of OLEDs. Their solubility, thermal properties, UV-visible absorption and photoluminescence behaviors were investigated. They were found to be soluble in various organic solvents such as tetrahydrofuran (THF), dimethylformamide (DMF), toluene and chloroform. It was also found that the UV-visible absorption and photoluminescence behaviors of these copolymers were similar to those of pristine $AlQ_3$. Green organic light-emitting diodes (OLEDs) have also been fabricated using these copolymers as light emission/electron transport components obtained easily by spin coating, and their current density voltage (J-V) curves were compared. The OLED device of the copolymer 3 had the lowest turn-on voltage of about 2 V compared to other copolymer types devices.

• Journal of Biomedical Engineering Research
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• v.8 no.1
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• pp.29-40
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• 1987

2-Hydroxyethyl methacrylate(HEMA) was copolymerized with allyltrimethylsilane- (ATMS) and allylt.imethoxysilane(ATMOS) at 70。C in N, N'dimethylformamide- (DMV) using $\alpha$ , $\alpha$'-azobisisobutyronitrile(AIBN). The compositions of unreacted monomers were determined by gas chromatographic analysis. The monomer reactivity ratios were determined by Fireman-Ross, Helen-Tiidus and intersection methods. The average values are as follows : $$r_1(HEMA) : 6.62 $\pm$ 0.07, r_2(ATMS) : 0.07 $\pm$ 0.01 for HEMA-ATMS system.$$ $$r_l(HEMA) : 4.09 $\pm$ 0.14, r_2(ATMOS) : 0.06 $\pm$ 0.01 for HEMA-ATMOS toys tem.$$ The lower rl(HEMA) In the HEMA-ATMOS system as compared to HEMA ATMS system may be contributed to higher relative reactivity of ATMOS toward the poly(HEMA) radical. The compositions of synthesized copolymers were determined from silicon con tents estimated gravimetrically. The thermal stabilities of the copolymers were investigated by thermogravimetry(TG). The enthalpic changes associated with the endothermic transition were evaluated by differential scanning calorimetry(DSC). The swelling properties of the copolymers in water were also investigated.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.2
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• pp.145-148
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• 2001

The bulk photopolymerization of 2-hydrxyethylmethacrylate(HDMA) with phenylsilane was perforemed to produce poly(HEMA)s containing phenylsilyl moiety presumably as an end group. This result, are the same as that of thermal polymerization. It was found that while the polymerization yields and intrinsic viscosities decreased, the TGA residue yields and the relative intensities of SiH IR stretching bands increased with increasing molar ratio of phenylsilane over HEMA. The phenylsilane seemed to significantly influence on the photopolymerization as both chain initiation and chain transfer agents.

• Journal of the Korean Chemical Society
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• v.39 no.5
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• pp.421-426
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• 1995

The hydrogels of hydrophilic three-dimensional methacrylate polymer networks were prepared from 2-hydroxyethyl methacrylate (HEMA) and ethylene glycol dimethacrylate (EDGMA) in aqueous solution. The interaction of water with the hydrophilic methacrylate polymers in the hydrogels was studied by pulse NMR spectroscopy. The spin-lattice relaxation times (T1) of low water content hydrogels showed the different double environments, resulting in two spin-lattice relaxation times (T1a and T1b). The values of T1a and T1b were 16.4${\times}$10-3 sec and 58.2${\times}$10-3 sec for a p(HEMA)-(10% H2O) system, and 13.2${\times}$10-3 sec and 23.1${\times}$10-3 sec for a crosslinked EGDMA-p(HEMA)-(10% H2O) system, respectively. The spin-spin relaxation times (T2) of the hydrogels were also measured as a function of water content in the p(HEMA)-(H2O)n and crosslinked EGDMA-p(HEMA)-(H2O)n system. The values of T2 were approximately 10 times less than those of T1 in agreement with the principles of spin relaxations.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.2
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• pp.87-90
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• 2000

Poly(HEMA)s have been used as the optometric material for the preparation of soft contact lens. The bulk thermal polymerization of 2-hydroxyethyl methacrylate (HEMA) with various hydrosilanes such as $phSiH_3$, $phMeSiH_2$, and $ph2SiH_2$ were performed to produce poly(HEMA)s containing phenylsilyl end moeity. It was found for thermal polymerization that while the polymerization yield and polymer molcular weights decreased as the relative phenylsilane concentration increases, the TGA residue yields and the relative intensities of SiH IR stretching bands increased as the relative hydrosilane concentration increases over HEMA. The polymerization yield, molecular weight, and TGA residue for the thermal polymerization were higher than those for the photo polymerization. Thus, the hydrosilanes significantly influence on the polymerization as both chain-initiation and chain-transfer agents.

• Journal of the Korean Chemical Society
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• v.53 no.3
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• pp.340-344
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• 2009

HEMA/vinyl-substituted polyphosphazene was prepared by the ring-opening polymerization of phosphonitrillic chroride trimer at $200{\sim}300\;{^{\circ}C}$, followed by Grignard reaction with vinyl magnesium bromide and then by the reaction with HEMA(2-hydroxyethyl methacrylate). HEMA/vinyl-substituted polyphosphazene was copolymerized with EGDMA(ethylene glycol dimethacrylate; used as a cross-linker for the free-radical copolymerization), NVP (N-vinyl-pyrrolidone) in the presence of AIBN (azobisisobutyronitrile) as a radical initiator. The oxygen transmissibility, water content and visible-ray transmissibility of the resulting copolymer were measured to be Dk/t 88, 30.89% and 87%, respectively, indicating that the copolymer can be used as a good contact lens material.

• KSBB Journal
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• v.11 no.5
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• pp.557-564
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• 1996

The interaction between poly(2-hydroxyethylmethacrylate)(poly(HEMA)) which is a material of contact lens containing approximately 45%o water and water soluble amino acids (alanine, arginine, glycine, lysine, methionine, proline, and serine) was investigated by using FT-IR and Raman spectroscopy. The results revealed that arginine and lysine had the strongest interaction with poly(HEMA) among amino acids. The interaction depended on the quantity of charges on ammo acids. They interacted predominately with hydroxyl groups in poly(HEMA).

• Bulletin of the Korean Chemical Society
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• v.4 no.4
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• pp.162-169
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• 1983

The swelling and stress-elongation experiments have been performed for two kinds of gels of tactic poly (2-hydroxyethyl methacrylate) (P-HEMA) with varying crosslinker concentrations. The gels of isotactic and syndiotactic P-HEMA were swollen in aqueous salt solutions upon varying molal concentrations. The solute used were NaCl, $MgCl_2$, $Na_2SO_4$, $MgSO_4$ and urea. The water content at equilibrium swelling and the salt partition coefficient were determined, and stress-elongation curves of the gels were obtained. From these results, the effective number of chain (${\nu}_e$) and the Flory-Huggins interaction parameter (${\chi}_1$) were also obtained. The swelling experiment was also performed under varying solvents, and the degree of swelling was determined. The solubility parameter of P-HEMA was obtained as 13.4 (cal/mole)$^{l/2}$ using the correlation between the degree of swelling and the solubility parameter (${\delta}_1$) of solvents. The mechanical properties of syndiotactic P-HEMA is stronger than that of isotactic P-HEMA, and the water content of both gels become smaller when the crosslinking increases. Isotactic P-HEMA contains more water content than syndiotactic P-HEMA does.

• Polymer(Korea)
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• v.29 no.5
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• pp.463-467
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• 2005

In order to enhance the actuation force of ionic polymer-metal composite (IPMC) made with the acrylic copolymer of fluoroalkyl methacryate, acrylic acie, and 2-hydroxyethyl methacrylate(HEMA), the hydroxy group of HEMA was corsslinked with 1,3-diethoxy-1,1,3,3-tetramethyldisiloxane. The water uptake was reduced and the mechanical strengths and the actuation force of the membrane was improved by crosslinking. However, current and deformation responses of IPMC were decreased by crosslinking.