• Journal of the Korean Chemical Society
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• v.16 no.5
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• pp.314-319
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• 1972

N-Methyl-p-aminophenol was polymerized by oxidative couplng in the aqueous iron chelate solution in the presence of oxygen, and black precipitate of oligo-(N-methyl-p-aminophenol) was formed quantitatively. In this oxidative polymerization reaction, methyl group attached to N in the monomer was partly eliminated, and it was clarified by the infrared spectra from the fact that the absorption of ${\delta}\;asym\;CH_3\;1460\;cm^{-1}$ and ${\delta}\;sym\;CH_3\;1380\;cm^{-1}$ in acetone insoluble fraction was much weaker than that in acetone soluble fraction. From Thermo-gravimetric analysis, oligo-(N-methyl-p-aminophenol) showed about 40% weight loss at $600^{\circ}C$ and it was less heat-resistant than oligo (p-aminophenol) that methyl group was not contained. In pyrolysis of oligo-(N-methyl-p-aminophenol) in He atmosphere, monomer N-methyl-p-aminophenol and water were formed, and in the pyrolytic gases, $H_2,\;CO,\;CO_2$ were detected by gas chromatography. From the above facts, to the structural change on oligo-(N-methyl-p-aminophenol) when it was heat-treated, it was considered that original linear structure was partly degraded, and the most of the oligomer was to go in with melt polycondensation to form polymer, and heat-resistant cyclic structure was formed at a time.

• Applied Chemistry for Engineering
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• v.10 no.3
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• pp.427-431
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• 1999

Copolyester resins for the coil coating process of aluminium and steel strip were synthesized and their thermal properties, molecular weight and solvent solution characteristics were examined. Copolyesters were obtained by two step reactions. The first step was to prepare bishydroxyethyl terephthalate (BHET), bishydroxyneopentyl terephthalate (BHNPT), bishydroxyethyl isophthalate (BHEI), bishydroxyneopentyl sebacate (BHNPS), bishydroxyneopentyl adipicate (BHNPA) and bishydroxyethyl adipicate (BHEA) oligomers by esterification reactions. The second step was the polycondensation reaction utilizing those oligomers to obtain relatively high molecular weight copolyesters (Mw = 30,000~59,000 g/mol) as measured by GPC. These copolyesters were amorphous polymers as shown by DSC without $T_m$ peaks probably due to the kink structure introduced by BHET oligomer and relatively large free volume by bulky BHNPT and BHNPS oligomers. The copolyester samples with half of BHET oligomer substituted by BHNPT while keeping BHEI (0.3 mole) and BHNPS (0.1 mole) ratio constant showed glass transition temperature above $40^{\circ}C$ and good solubility in toluene both at low ($-5^{\circ}C$) temperature and room temperature.

• Polymer(Korea)
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• v.29 no.6
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• pp.575-580
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• 2005

The hydroxy terminated aliphatic hyperbranched polyesters having different generations were synthesized by using melt polycondensation procedure. Then, the terminal groups of hyperbranched polyesters were modified by using acryloyl chloride and characterized by $\^{1}H$-NMR and GPC techniques. As a result of the modification of terminal groups for hyperbranched polyesters, the phase of the polymers were changed from sticky solid to high viscous liquid indicating that the glass transition temperatures of modified hyperbranched polyesters were lower than the original one. The thermal stabilities of hydroxy terminated hyperbranched polyesters were higher than those of terminal group-modified polymers.

• Polymer(Korea)
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• v.29 no.6
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• pp.571-574
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• 2005

The aromatic hyperbranched polyamide was synthesized from 5-aminoisophthalic acid by direct polycondensation with triphenylphosphite (TPP) catalyst as a condensing agent. The modification of end-groups in the resulting hyperbranched polymer (HBP) with various alkyl alcohols were conducted. The modification of end-groups of HBP by alkyl groups resulted in an improved solubility in the THF comparing to that of the carboxylic acid-terminated aromatic HBP, Also, 10 wt$\%$ weight loss temperature decreased by increasing the length of alkyl group.

• Bulletin of the Korean Chemical Society
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• v.27 no.7
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• pp.981-985
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• 2006

Novel copolymers consisting of poly(2-hydroxyethyl aspartamide-co-N,N'-dimethyl-1,3-propane aspartamide) (PHEA-DPA) were prepared from polysuccinimide (PSI), which is the thermal polycondensation product of aspartic acid, via a ring-opening reaction with N,N'-dimethyl-1,3-propane diamine (DPA) and ethanolamine. The prepared water-soluble copolymer was then crosslinked by reacting it with hexamethylene diisocyanate to provide the corresponding gel. The swelling behavior and morphology of the crosslinked hydrogels were investigated. The degree of swelling decreased with increasing crosslinking reagent due to the higher crosslinking density. It was also confirmed that the swelling property is affected by pH. At low pH (< pH 4), swelling is increased due to the ionization of DPA with a tertiary amine moiety. In addition, a reversible swelling and de-swelling behavior was demonstrated by adjusting the pH of the solution. The prepared hydrogels showed a well-interconnected microporous structure with regular 5-20 $\mu$m sized pores.

• Analytical Science and Technology
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• v.12 no.5
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• pp.436-440
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• 1999

Antistatic property and crystallization behavior of antistatic poly(ethylene terephthalate) (PET) were studied by feeding antistatic agents into polycondensation reactor. Glass transition and melting temperature of antistatic PET were decreased by poly(ethylene glycol) (PEG) component of antistatic agent. The crystallization rate of antistatic PET was inhibited by decreasing crystallization temperature. Thermal properties and crystallization behavior was affected POAG content of antistatic agent rather than sodium alkylsulfonate of it. The main antistatic component of antistatic agent was POAG. The main role of sodium alkylsulfonate was increasing melt viscosity of antistatic poly(ethylene terephalate) polymer.

• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.1041-1045
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• 1999

Three polysiloxaneimide(PSI) as membrane material were prepared by polycondensation of three aromatic dianhydrides(6FDA, BTDA, PMDA) with one siloxane-containing diamine(SIDA, aver. MW. 800). The PSIs were rubbery polymers containing 30~40 wt % of flexible siloxane chains and exhibited low density, high fractional free volume and low surface energy. They were used for pervaporation experiments with 0.05 wt % of four organic aqueous solutions containing ethyl acetate, methylene chloride, trichloroethylene, and toluene, respectively. With increasing hydrophobicity of organic solvents, both pervaporation selectivity and pemeation flux increase.

• Korean Journal of Materials Research
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• v.26 no.12
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• pp.696-703
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• 2016

In this study, we intensively investigated the effect of conductive additive amount on electrochemical performance of organic supercapacitors. For this purpose, we assembled coin-type organic supercapacitor cells with a variation of conductive additive(carbon black) amount; carbon aerogel and polyvinylidene fluoride were employed as active material and binder, respectively. Carbon aerogel, which is a highly mesoporous and ultralight material, was prepared via pyrolysis of resorcinol-formaldehyde gels synthesized from polycondensation of two starting materials using sodium carbonate as the base catalyst. Successful formation of carbon aerogel was well confirmed by Fourier-transform infrared spectroscopy and $N_2$ adsorption-desorption analysis. Electrochemical performances of the assembled organic supercapacitor cells were evaluated by cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy measurements. Amount of conductive additive was found to strongly affect the charge transfer resistance of the supercapacitor electrodes, leading to a different optimal amount of conductive additive in organic supercapacitor electrodes depending on the applied charge-discharge rate. A high-rate charge-discharge process required a relatively high amount of conductive additive. Through this work, we came to conclude that determining the optimal amount of conductive additive in developing an efficient organic supercapacitor should include a significant consideration of supercapacitor end use, especially the rate employed for the charge-discharge process.

• Journal of Korean Ophthalmic Optics Society
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• v.8 no.2
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• pp.31-35
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• 2003

Several poly(6-dialkylamino-1,3,5-triazine-2,4-dithioxylene) derivatives were synthesized by the polycondensation of 6-dialkylamino-1,3,5-triazine-2.4-dithiol with m- and p-dibromide xylene in a cetyltrimethyl ammonium bromide at $70^{\circ}C$ for 24h. The synthesized derivatives had refractive Indexes of 1.580~1.697 and had molar absorptivity of 97~196.6. In these derivatives, we knew that they are a polymer having high refraction indexes without double refraction because they contain triazine rings and sulfur atoms with high electron density.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.4
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• pp.1367-1372
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• 2010

Copoly(ether-ether-ester)s having flexible side chain were synthesized by polycondensation. Intrinsic viscosities of polymers were between 0.42 and 0.78dl/g in tetrachloroethane. The polymer structures were investigated by $^1H$-NMR and FT-IR, and thermal and liquid crystalline properties of polymers were measured by DSC, TGA, POM and XRD. As results of investigations, synthetic copolymers exhibited lower melting temperature than homopolymers. When the biphenylene units contents in copolymer were more than 60 mol %, nematic mesophase was observed, and the mesophase of synthetic polymers was dependent upon biphenylene content.