• Journal of the Korean Chemical Society
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• v.54 no.6
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• pp.723-726
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• 2010

An efficient and simplified protocol for $NaHSO_4/SiO_2$ catalyzed solvent-free synthesis of $\beta$-enaminone and 2-methylquinolin-4(1H)-one derivatives under microwave irradiation is described. A series of functionalized derivatives have been synthesized in shorter reaction times with moderate to good yields. The use of milder catalyst in non-conventional method offers significant advantages over conventional methods, such as higher selectivities, simplicity, solvent-free reaction and non-environmental polluting conditions.

• Journal of the Korean Chemical Society
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• v.52 no.4
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• pp.369-379
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• 2008

• Journal of the Korean Chemical Society
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• v.55 no.3
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• pp.486-489
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• 2011

Potassium dihydrogen phosphate was found to be an efficient catalyst for the Pechmann condensation of phenols with ethyl acetoacetate, leading to the formation of coumarins under microwave-irradiation and solvent-free condition. This procedure offers several advantages, including the low loading of catalysts, high yields, clean reactions, short reaction time for the synthesis of coumarins.

• Journal of Adhesion and Interface
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• v.8 no.4
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• pp.8-13
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• 2007

In this study, solvent-free waterborne polyurethanes (SWPU) were synthesized with teramethylxylene diisocyanate (TMXDI), poly(tetramethylene glycol) (PTMG) and polycarprolactone (PCL) and different mole ratio of dimethylol proponicacid (DMPA). The effect of ionic contents in the solvent-free waterborn polyurethane on thermal, mechanical properties and adhesion strength were studied. Glass transition temperature (Tg) were in range of $-70{\sim}-50^{\circ}C$ and increased as PCL contents increased in polyol. With more incorporation of PCL and DMPA contents in SWPU, tensile strength, adhesion strength and heat resistance of SWPU increased, while the elongation decreased.

• Journal of the Korean Chemical Society
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• v.51 no.6
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• pp.591-594
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• 2007

• Journal of the Korean Chemical Society
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• v.51 no.2
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• pp.115-124
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• 2007

A series of α, β-unsaturated ketones are synthesized by Crossed - Aldol condensation reaction, from ecofriendly 6-methoxy-2-naphthyl ketones and substituted benzaldehydes under solvent free conditions using silica-sulfuric acid as a catalytic reagent. The yields of ketones are more than 90% and the catalyst was reusable for further run. There is no appreciable decrease in the yield of product and the activity of catalyst. These chalcones were characterized by their physical constants and spectral data (IR, 1H-, 13C-NMR and Mass). These spectral data are subjected to correlate various Hammett substituent constants with single and multiparameter correlation equations. From the results of statistical analysis the influence of electronic effects of substituents on the spectral data of the ketones were explained.

• Journal of the Korean Chemical Society
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• v.51 no.4
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• pp.346-351
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• 2007

Efficient stereoselective synthesis of α,β-Unsaturated acids, α-Cyanoacrylonitriles and α-Cyanoacrylates has been carried out in the presence of NaHSO4·SiO2 under solvent?free conditions with an E-geometry.

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.584-589
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• 2005

Structured triacylglycerol (SL-TAG) was synthesized by enzymatic interesterification with algae oil and soybean oil in solvent-free system. Structured di- and monoacylglycerol (SL-DAG/MAG) were produced by glycerolysis with SL-TAG and glycerol catalyzed by lipase. Reactions were performed by sn-1.3 specific Lipozyme RM IM lipase from Rhizomucor miehei (interesterification, 11%; glycerolysis 5% by weight of total substrates) in solvent-free system using stirred-batch type reactor. SL-DAG/MAG contained TAG (42,3 area%), 1,3-DAG (19.2 area%), 1,2-DAG (22.2 area%), MAG (16.0 area%), and free fatty acid (0.2 area%). Iodine and saponification values of SL-DAG/MAG were 208.8 and 179.6, respectively. SL-DAG/MAG appeared yellowish in color.

• Applied Chemistry for Engineering
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• v.24 no.2
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• pp.171-176
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• 2013

The need of volatile organic compound (VOC) free coating material has been increased to solve environmental problems such as the global warming. Nowadays, about 70~80% of coating materials used in the worldwide are a liquid type. Therefore, the development of non-solvent coating material that can minimize VOCs emissions is necessary to solve the global warming problem. In this study, acrylic monomers were added to develop non-solvent paints in order to improve disadvantages of the poor adhesion of a conventional phenolic resin caused by acidification. As a result, the blend resins of 2.818 Mpa phenol- formaldehyde resin/poly methyl methacrylate (PE/PMMA) has the best properties and performances for the adhesives.

• Journal of the Korean Ceramic Society
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• v.33 no.5
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• pp.485-494
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• 1996

Silica Aerogels with the density and porosity of 0.1g/cm3 and 96% were synthesized by two different supercri-tical drying processes (i.e additional solvent and intial pressure methods) Isoptopanol was chosen as sol-gel and supercritical drying solvents in order to synthesize aerogels at the lower temperature and pressure because the critical values of isopropanol are lower than those of methanol and ethanol commonly used. The P-V-T relationship of isopropanol was experimentally described for optimizing supercritical drying conditions such as the amount of extra solvent and supercritical drying temperature and pressure. In the addional solvent method monolithic and transparent aerogels were obtained by supercritical drying at 25$0^{\circ}C$ and 900 psing after 40% of the reactor volume was filled with isopropanol. Crack-free aerogels were synthesized at 25$0^{\circ}C$ and 1100~1200 psig by the initial pressure method with an intial nitrogen gas pressure of 400 psig and the isopropanol amount of 5% of the reactor volume.