• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.6
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• pp.50-55
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• 2014

An oxidized starch was modified for surface sizing via etherification and esterification. Propylene oxide (PO), sodium monochloroacetate (SMCA), and acrylonitrile (AN) were used as etherification, and vinyl acetate monomer (VAM), maleic anhydride (MA), fumaric acid (FA), and itaconic acid (ITA) were used for esterification. Esterification and etherification of starch decreased both Brookfield viscosity and Brabender viscosity substantially even though the solids level was increased by 2% from 14 to 16%. Surface sizing performance of starches in tensile strength, stiffness and compressive strength was improved by esterification and etherification of the oxidized starch. Especially, SMCA etherification was found to be the most effective modification method.

• Clean Technology
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• v.11 no.4
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• pp.189-194
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• 2005

Carboxymethylcellulose(CMC) which is water-soluble fiber was manufactured by mercerization and etherification in the earlier study. Experimental parameters were conversion time for each step, concentration of reagent and temperature. To know the presence of functional group, CMC was analyzed by FT-IR(Fourier Transform Infrared) spectroscopy. Ethanol was recovered using evaporator and purity of ethanol analyzed by GC-MASS was 97% and 83% after mercerization and etherification respectively. For the pilot plant, if CMC is folded by 40 times it showed maximum efficiency. Maximum solubility was obtained when the ratio of NaOH and MCA is 3 : 4.5.

• Bulletin of the Korean Chemical Society
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• v.16 no.4
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• pp.363-369
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• 1995

Hydroiminoacylations of allyl and homoallyl alcohol and their derivatives with benzaldimine by Wilkinson's complex have been studied. All these terminal alkene derivatives except allyl alcohol were hydroacylated according to anti-Markownikoff's rule to give the corresponding linear alkyl compounds without showing oxygen directing effect, even though hydroiminoacylation of 3-acetoxy-1,5-hexadiene showed strong allyloxy directing effect over homoallyloxy directing effect in a 92:8 ratio. Solvolysis of 4-acetoxy-1-phenylbutan-1-one, previously prepared by hydroiminoacylation, in ethanol led to etherification giving 4-ethoxy-1-phenylbutan-1-one through neighbouring group participation, while that of 5-acetoxy-1-phenylpentan-1-one led to common transesterification giving 5-hydroxy-1-phenylpentan-1-one. Application of branched alkanols such as isopropanol and t-butanolin solvolysis of 4-acetoxy-1-phenylbutan-1-one underwent competition between etherification and transesterification.

• Clean Technology
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• v.13 no.3
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• pp.201-207
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• 2007

Carboxymethylcellulose (CMC), which is water-soluble at room temperature, was synthesized from cellulose in this study. Experimental parameters included reaction temperature, time, concentration of NaOH, and monochloroacetic acid (MCA). In mercerization and etherification, solubility and degree of substitution (DS) increased when NaOH (or MCA) concentration increased and maximum solubility and DS were achieved when NaOH or MCA was 30%. The effect of MCA concentrations on the DS was larger than that of the NaOH concentration. Tensile strength of the CMC was decreased by the increases of reaction time, reagent concentration and reaction temperature. Tensile strength also decreased by NaOH and MCA. However, low decrease of tensile strength was observed in near neutral region.

• Korean Chemical Engineering Research
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• v.50 no.2
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• pp.251-256
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• 2012

Etherification of n-butanol to di-n-Butyl Ether was carried out over Keggin $H_{3+x}PW_{12-x}Nb_xO_{40}$ (x=0, 1, 2, 3) and $H_{6+x}P_2W_{18-x}Nb_xO_{62}$ (x=0, 1, 2, 3) Wells-Dawson heteropolyacid catalysts. Niobium-substituted Keggin and Wells-Dawson heteropolyacid catalysts with different niobium content were prepared. Successful preparation of the catalysts was confirmed by FT-IR, ICP-AES, and $^{31}P$ NMR analyses. Their acid properties were determined by $NH_3$-TPD (Temperature-Programmed Desorption) measurements. Heteropolyacid catalysts showed different acid properties depending on niobium content in both series. The correlation between acid properties of heteropolyacid catalysts and catalytic activity was then established. Acidity of Keggin and Wells-Dawson heteropolyacid catalysts decreased with increasing niobium content, and conversion of n-butanol and yield for di-n-butyl ether increased with increasing acidity of the catalysts, regardless of the identity of heteropolyacid catalysts (without heteropolyacid structural sensitivity). Thus, acidity of heteropolyacid catalysts served as an important factor determining the catalytic performance in the etherification of n-butanol to di-n-Butyl Ether.

• Korean Chemical Engineering Research
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• v.46 no.2
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• pp.279-285
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• 2008

The etherification of 2-naphthol with ethanol has been carried out over various solid acid catalysts. CNS, CNSWS, SCMS, MCF, and SBA-15 with and without sulfonic acid were used in this study as solid acid catalysts. The conversion of 2-naphthol and the selectivity of 2-naphthyl ethyl ether were obtained at reaction temperature = $180^{\circ}C$, $LHSV=1h^{-1}$, ethanol/2-naphthol molar ratio = 20 using a fixed-bed down flow reactor. The conversion of 2-naphthol and the selectivity of 2-naphthyl ethyl ether over silica group catalysts were higher than them over carbon group catalysts. The conversion of 2-naphthol was 70-90% and the selectivity of 2-naphthyl ethyl ether was more than 90% over silica group solid acid catalysts. It was performed XRD, SEM, TEM, and $NH_3-TPD$ to characterize solid acid catalysts.

• Journal of the Korean Chemical Society
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• v.56 no.6
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• pp.706-711
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• 2012

Hindered phenols and alcohols were protected as their corresponding ethers using different alkylating agents in presence of KOH/DMSO under microwave irradiation. $$R-OH\;{KOH/DMSO,\;R^{\prime}-X,\;MW \\{\vec{10-15\;Mins,\;80%-90%\;Yield}}}\;R^{{/}^O{\backslash}}R^{\prime}$$.

• Polymer(Korea)
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• v.26 no.5
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• pp.599-606
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• 2002

In this study, 4,4'-tetraglycidyl diaminodiphenyl methane (TGDDM)/polyamideimide (PAI) blends were cured using diaminodiphenyl sulfone (DDS). And the effect of addition of different PAI contents to neat TGDDM was investigated in the thermal, mechanical, and morphological properties of the blends. The cure behavior and thermal stability of the cured specimens were monitored by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. Also, the critical stress intensity factor (K$\_$IC/) was measured in UTM, and the phase separation behavior and final morphology of TGDDM/PAI blends were examined in scanning electron microscopy(SEM). As a result, the cure temperature and cure activation energy (E$\_$a/) were decreased with increasing the PAI content. The decreasing of cure temperature and cure activation energy were probably due to the presence of secondary amine group of PAI backbone used as co-initiator. But, the decomposition activation energy (E$\_$t/) and K$\_$IC/ value were increased up to 5. 10 phr of PAI content, respectively and they were decreased above the PAI contents. These results were explained on the basis of chain scission reaction by etherification. And morphology of blends observed from SEM was confirmed in co-continuous structures.

• Bulletin of the Korean Chemical Society
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• v.24 no.4
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• pp.460-466
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• 2003

For the drug master file (DMF) of ketoconazole, four impurities (1-4) contained in ketoconazole were synthesized. During the synthesis of 2, a new synthetic method of 1,4-dihydropyrazine was established. To oxidize the aminoalcohol (2j) to the aminal (2j-1), the standard Swern oxidation condition was modified to mask the nucleophilicity of the amino group temporarily using one equivalent of acetic acid. Derivative 3 was synthesized via regioselective bromination at the 2 position of the 4-aminophenol derivative (3a) using $Br_2$ in the presence of p-TsOH. The etherification of aryl bromide with the phenol derivative (1f) was accomplished by a modification of the general Cu-mediated reaction condition using excess 1f itself as a solvent at elevated temperature (190 ℃).

• Bulletin of the Korean Chemical Society
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• v.28 no.10
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• pp.1777-1780
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• 2007

The synthesis of well-defined dendrons based on aliphatic polyether dendritic cores and glassy polystyrene peripheries is described. The synthetic route involves a combination of living anionic polymerization and a stepwise convergent method consisting of iterative Williamson etherification and hydroboration/oxidation reactions. On the basis of molecular weight, as characterized by gel permeation chromatography (GPC), the first generation dendron (Generation-1) shows a random coil conformation like a linear polystyrene, while higher generations (Generation-2 and 3) reveal globular forms in solution.