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Cho D.W.,Seoul National University | Shin J.,LS Cable Ltd. | Bae W.,Miwon Specialty Chemical Co. | Kim H.,Seoul National University | And 2 more authors.
Fluid Phase Equilibria | Year: 2012

In this study, high-pressure phase behavior data, the pressure-composition (P-x) isotherms for the CO 2+T3EGDMA and CO 2+T4EGDMA binary mixture system, were measured using the static method with a variable-volume view cell at temperatures ranging from 313.2 to 363.2K. The experimental data correlation was performed using the Peng-Robinson Equation of State (PR-EOS) and the van der Waals one-fluid mixing rule. The critical constants for the PR-EOS were estimated using the several group contributions. The acentric factor was estimated using the Lee-Kesler method. The Joback method shows the better correlation results than the others. © 2011.


Cho D.W.,Seoul National University | Shin J.,LS Cable Ltd. | Bae W.,Miwon Specialty Chemical Co. | Kim H.,Seoul National University | Seo K.W.,Ajou University
Journal of Chemical and Engineering Data | Year: 2012

High-pressure phase behavior measurements of (CO 2 + heptadecafluoro-1-decene) and (CO 2 + nonafluoro-1-hexene) binary mixture systems were carried out using a variable volume view cell. The experimental range of temperature and pressure are from 313.2 K to 343.2 K and up to 15 MPa, respectively. The correlation was performed using the Peng-Robinson equation of state and the van der Waals one-fluid mixing rule. The critical constants, T c and P c, were estimated by the several group contribution methods. The acentric factor was estimated by the Lee-Kesler method. © 2012 American Chemical Society.


Kwon J.M.,Seoul National University | Cho D.W.,Seoul National University | Bae W.,Miwon Specialty Chemical Co. | Kim H.,Seoul National University
Journal of Chemical and Engineering Data | Year: 2011

In this study, the high-pressure phase behavior of carbon dioxide + tetrahydrofurfuryl acrylate and carbon dioxide + tetrahydrofurfuryl methacrylate mixtures was studied using a variable volume view cell at temperatures ranging from (313.15 to 363.15) K and pressures of up to 18 MPa. The experimental results were correlated with the Peng-Robinson equation of state using the van der Waals one-fluid mixing rule with one adjustable binary interaction parameter. We compared the Nannoolal-Rarey and Constantinou-Gani group contribution methods for the correlation of the experimental results. © 2011 American Chemical Society.


Cho D.W.,Seoul National University | Shin J.,LS Cable Ltd. | Shin M.S.,Eulji University | Bae W.,Miwon Specialty Chemical Co. | Kim H.,Seoul National University
Journal of Chemical Thermodynamics | Year: 2012

Lactate esters synthesized with lactic acid and ester are used as solvents and reactants in various industries, including agricultural chemistry, pharmaceuticals, electronics, and fine chemicals. Among lactate esters, high purity propyl lactate and butyl lactate are used to produce fine chemicals and in the synthesis of chiral intermediates for use in pesticides and drugs. However, distillation for the removal of propyl lactate and butyl lactate alters or degenerates products due the high boiling points of these two lactate esters. This problem can be solved by supercritical fluid extraction (SCFE) at lower temperatures. SCFE process requires high-pressure phase behavior data on CO 2 and lactates for its design and operation. In this study, high-pressure phase behavior of propyl lactate and butyl lactate in CO 2 was measured from (323.2 to 363.2) K using a variable-volume view cell apparatus. Experimental data were well correlated by the Peng-Robinson equation of state using the van der Waals one-fluid mixing rules. The critical constants were estimated by the Joback method, the Constantinou-Gani method, and the Nannoolal-Rarey method. Acentric factor was estimated by the Lee-Kesler method. © 2011 Elsevier Ltd. All rights reserved.


Shin J.,Seoul National University | Bae W.,Miwon Specialty Chemical Co. | Kim H.,Seoul National University
Korean Journal of Chemical Engineering | Year: 2010

We carried out a dispersion polymerization of N-vinyl-2-pyrrolydone using fluorine-based surfactants, which included poly(heptadecafluorodecyl acrylate) (PHDFDA) or poly(heptadecafluorodecyl methacrylate) (PHDFDMA) in supercritical carbon dioxide (scCO2). An FE-SEM and an image analyzer were used to characterize particle morphology, size, and size distribution of the resulting polymer taking into account effect of the surfactant, initiator, and monomer concentrations. © 2010 Korean Institute of Chemical Engineers, Seoul, Korea.


Shin J.,Seoul National University | Bae W.,Miwon Specialty Chemical Co. | Kim H.,Seoul National University
Colloid and Polymer Science | Year: 2010

Cross-linked poly(methyl methacrylate) particles were prepared via dispersion polymerization in supercritical carbon dioxide (scCO2) using poly(heptadecafluorodecyl methacrylate) (PHDFDMA) and 2,2'- azobisisobutyronitrile as the dispersant and the initiator, respectively. The following chemicals were used as cross-linking agents: ethylene glycol dimethacrylate (EGDMA), 1,4-buthanediol di(meth)acrylate (1,4-BD(M)A), and trimethylolpropane trimethacrylate. PHDFDMA was synthesized by solution polymerization in scCO2. We investigated the effect of the chemical structure, concentration of the cross-linking agents, reaction pressure, and CO2density on the morphology, the polydispersity, and the cross-linking density of polymer particles. The resulting polymer particle was characterized by field emission SEM, differential scanning calorimetry, and thermal gravimetric analysis. The crosslinked PMMA particles is more agglomerate as the crosslinking agent concentration increased and as pressure decreased at constant temperature. Glass-transition temperature (Tg) of the resulting polymer increased as the crosslinking agent increased with temperature and pressure increasing at the same CO2 density. Decomposition temperature is slightly increased as 1,4-BDA concentration increased. From these results, we can confirm that the thermal stability of the polymer increased as the cross-linking agent and EGDMA is the best cross-linking agent in term of the thermal stability. © Springer-Verlag 2009.


Shin J.,Seoul National University | Cho D.W.,Seoul National University | Bae W.,Miwon Specialty Chemical Co. | Kim H.,Seoul National University
Colloid and Polymer Science | Year: 2010

Silica/perfluoroalkyl methacrylate polymer (PHDFDMA) particles were prepared using various types of silica by polymerization in supercritical carbon dioxide. There are three steps in the fabrication of inorganic/organic hybrid composites: silane treatment, polymerization, and soxhlet extraction. After these steps, we observed the morphology of silica/PHDFDMA particles using field emission scanning electron microscope and transmission electron microscope. From these analyses, we can confirm that the silica/PHDFDMA core/shell particles were obtained when we used Ludox and silica gel as a silica template. On the other hand, core/shell particles were not formed when using fused silica and precipitated silica. In addition, to confirm the amount of polymer on silica, we performed an analysis using thermogravimetric analysis and electron probe micro-analyzer. In this case, PHDFDMA was approximately 20 wt.% on the silica gel and 40 wt.% on the Ludox, respectively. When using fused silica and precipitated silica as a template, amount of PHDFDMA on silica was maximum 5 wt.% and over 40 wt.%, respectively. From these results, to obtain enough PHDFDMA encapsulated silica particle, colloidal silica, Ludox is the best template in four different types of silica. © 2009 Springer-Verlag.


Shin J.,Seoul National University | Cho D.W.,Seoul National University | Bae W.,Miwon Specialty Chemical Co. | Kim H.,Seoul National University
Korean Journal of Chemical Engineering | Year: 2010

Dispersion polymerization of N-vinyl caprolactam (NVCL) was carried out in supercritical carbon dioxide (scCO2) using three surfactants. The polymerization was performed in the presence of fluorine-based poly(heptadecafluorodecyl acrylate) (PHDFDA), poly(heptadecafluorodecyl methacrylate) (PHDFDMA) or siloxane-based PDMS-g-pyrrolidonecarboxylic acid (Monasil PCA) as a surfactant. FE-SEM and image analyzer were used to characterize particle morphology, size, and size distribution. When fluorine-based surfactants were used, spherical PVCL particles were obtained. Using Monasil PCA resulted in agglomerated and irregular polymer particles. The effect of concentration of surfactants, initiators, and monomer, and reaction pressure on the particle morphology, average particle size and particle size distribution (PSD) was also investigated with fluorine-based surfactant, PHDFDA or PHDFDMA. © 2010 Korean Institute of Chemical Engineers, Seoul, Korea.


Trademark
Miwon Specialty Chemical Co. | Date: 2011-12-06

Chemicals for use in the manufacture of adhesives, coatings, electronics, and inks, namely, methacrylate monomer; methacrylate oligomer; acrylate monomer; acrylate oligomer.

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