• 한국염색가공학회지
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• 제17권3호
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• pp.1-7
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• 2005

Cationic dyeable polyester(CDP) was produced through melt blending of cationic chips having $2mol\%$ of sodium salt of dimethyl ester of 5-sulfoisophthalic acid(DMS salt) and normal polyester chips in different proportions to obtain yarns having varying amount of comonomer in the fiber. The modified polyesters showed increased moisture regain, decreased viscosity, lower softening point and improved antistatic characteristics, according to the amount of modifier. In dyeing at $100^{\circ}C$ the dyeing rate of cationic dyes with CDP fiber increased slowly than that of disperse dyes. In dyeing at $120^{\circ}C$ cationic dyes reached to equilibrium at 30min and disperse dyes at 10min. Cationic dyes in dyeing of CDP fabric have a better wash fastness compared with disperse dyes, also rubbing fastness of cationic dyes is better than that of disperse dyes. The light fastness of CDP fabric for cationic and disperse dyes is not good. The fastness of 75d/36f CDP fabric is higher than 75d/72f fabric. Solvent wicking fastness of CDP with cationic dyes is better than that of disperse dyes.

• 한국응용과학기술학회지
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• 제15권4호
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• pp.45-56
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• 1998

Methyl fructoside oleic acid polyester(MFPE), fructose-based sugar polyester, was synthesized by solvent-free, soap-free transesterification of methyl oleate with methyl fructoside(MF) as a sugar starting material in the presence of conventional potassium carbonate basic catalyst. Methyl fructoside was found to be an effective sugar starting material, because of its low softning point, high heat stability, high miscibility, and high reactivity than other sugars. Yield 98% of purified MFPE based on initial weight of MF was obtained at 1:5 of the molar ratio of methyl fructoside to methyl oleate, 2%(w/w) of potassium carbonate catalyst content, 20${\sim}$200mmHg of reduced pressure and $180^{\circ}C$ of reaction temperature. MFPE structure was confirmed by infrared and proton nuclear magnetic resonance spectroscopy. Physical properties of methyl of fructoside oleic acid polyester such as viscosity, HLB, solubility, color, refractive index, specific gravity, and density were similar to physical properties of sucrose polyesters(SPE) and vegetable oils. Then, it was elucidated that MFPE was sufficient to replace the SPE and conventional oils.

• 한국응용과학기술학회지
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• 제21권1호
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• pp.51-61
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• 2004

Reaction intermediates PCP/BZA (PBI) and tetramethylene bis(orthophosphate) (TBOP) wer synthesized from polycaprolactone (PCP) and benzoic acid (BZA) and from pyrophosphoric acid and 1,4-butanediol, respectively. Benzoic acid modified polyesters containing phosphorus (APTB-5, -10, -15) were synthesized by polycondensation of the prepared PBI (containing 5, 10, 15wt% of benzoic acid), TBOP, adipic acid, and 1,4-butanediol. The structure and characteristics of APTBs were examined using FT-IR, NMR, GPC, and TGA analysis. The increase of the amount of BZA in the synthesis of APTBs resulted in decrease in average molecular weight and kinematic viscosity. From the TGA analysis of APTBs, it was found that the afterglow decreased with the amount of BZA content at the high temperatures.

• 한국응용과학기술학회지
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• 제17권3호
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• pp.203-211
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• 2000

Pyrophosphoric lactone modified polyester(PATT) that contains two phosphorous functional groups in one unit base resin structure was synthesized to prepare a non-toxic reactive flame retardant coatings. Then the PATT was cured at room temperature with isocyanate, Desmodur IL, to get a two-component polyurethane flame retardant coatings(PIPUC). Comparing the physical properties of the films of PIPUC with the film of non-flame retardant coatings, there was no degradation observed in physical properties by the introduction of a flame-retarding component into the resin. We found that the char lengths measured by $45^{\circ}$Meckel burner method were $3.1{\sim}4.4cm$ and LOI values recorded $27{\sim}30%$. These results indicate that the coatings prepared in this study is good flame retardant one. The surface structure of coatings investigated with SEM does not show any defects and phase separation.

• Macromolecular Research
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• 제14권2호
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• pp.146-154
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• 2006

Organic and inorganic hybrid nanocomposites based on poly(ethylene 2,6-naphthalate) (PEN) and silica nanoparticles were prepared by a melt blending process. In particular, polymer nanocomposites consisting mostly of cheap conventional polyesters with very small quantities of inorganic nanoparticles are of great interest from an industrial perspective. The crystallization behavior of PEN/silica hybrid nanocomposites depended significantly on silica content and crystallization temperature. The activation energy of crystallization for PEN/silica hybrid nanocomposites was decreased by incorporating a small quantity of silica nanoparticles. Double melting behavior was observed in PEN/silica hybrid nanocomposites, and the equilibrium melting temperature decreased with increasing silica content. The fold surface free energy of PEN/silica hybrid nanocomposites decreased with increasing silica content. The work of chain folding (q) for PEN was estimated as $7.28{\times}10^{-20}J$ per molecular chain fold, while the q values for the PEN/silica 0.9 hybrid nanocomposite was $3.71{\times}10^{-20}J$, implying that the incorporation of silica nanoparticles lowers the work required to fold the polymer chains.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1067-1070
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• 2008

DuPont Teijin FilmsTM have developed engineered substrates for flexible electronics. Teonex(R) Q65 and Melinex(R) ST506/5004 are biaxially oriented semi-crystalline polyesters. Smooth planarised Teonex(R) Q65 and Melinex(R) ST506/504 emerge as suitable substrate materials for display backplanes and frontplanes. This contribution discusses the impact of applying a planariser coating to these films. Also, the effect of a more controlled finishing process treatment upon film shrinkage and CLTE is presented.

• 한국화재소방학회논문지
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• 제12권4호
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• pp.51-57
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• 1998

FRP용 모재수지로 다량 사용되는 불포화폴리에스터 수지(이소프탈산계, 비닐에스터계)의 내열성 및 연소특성을 열분석, 연소실험 및 SEM 관찰을 통하여 알아보았다. 열분석(TGA, D DSC) 결과 이소프탈산계 폴리에스터보다 비닐에스터수지의 내열 특성이 상대적으로 우수 한 것으로 나타났다. 연소실험 결과 이소프탈산계 폴리에스터는 수지에 유통이 생기면서 쉽 게 연소되었지만, 비닐에스터의 경우 연소 시 고체탄화물을 형성시켜 상대적으로 낮은 b burning rate 값을 보였다. 본 연구 결과 불포화 폴리에스터 수지가 연소될 때 많은 연기와 화염이 발생하므로 FRP 모재수지로 사용할 때 반드시 난연처리를 해야 함을 알 수 있었다.

• 공학논문집
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• 제3권1호
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• pp.235-242
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• 1998

곁가지에 탄소-탄소 이중결합과 탄소-탄소 삼중결합을 포함한 미생물 폴리($\beta$-하이드록시알카노에이트)에 실리콘 화합물과 브롬의 첨가반응을 수행하였다. IR spectrometer와 DSC를 이용하여 생성된 고분자를 분석한 결과, 실리콘 화합물이 첨가된 고분자는 결정성이 증가하였으며, 브롬이 첨가된 고분자는 유리전이 온도가 올라갔다. 브롬의 탄소-탄소 이중결함과 탄소-탄소 삼중결합에 대한 반응속도는 탄소-탄소 이중결합이 더 빠른 것으로 나타났다. 폴리($\beta$-하이드록시알카노에이트)에 코발트 화합물을 반응시킨 결과, 착물을 형성하여 가교반응이 일어났다.

• 한국의류학회지
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• 제25권1호
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• pp.124-131
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• 2001

To find out the effect of burn out print finishing for better quality of fabric, examined processing which could make less damages on the fiber because the biggest problem is remained fibers damage after burn out print finishing. Fiber damage examined to the condition of finishing material NaHSO$_4$and H$_2$SO$_4$, 3~10min., 100~13$0^{\circ}C$, glycerin. The fiber damages evaluated the break strength and the surface condition by SEM. Among satin, pile fabric which remained fiber is silk, warp knitted fabric which remained fiber is polyester, the fibers damage level were warp knitted fabric$0^{\circ}C$, glycerin and for 6 minutes by NaHSO$_4$. When carbonized by 20%. 50% and 70% to express textile design, carbonizing rate was not effect on the fiber damage very much. There was almost no damages with glycerine, and almost no damages during 3~6minutes fixation time, 10$0^{\circ}C$ steaming heat fixation by NaHSO$_4$and H$_2$SO$_4$. Without glycerine, there were damage by hydrolysis on polyesters surface and the fiver was broken by fixation time.

• Journal of Microbiology and Biotechnology
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• 제15권1호
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• pp.206-215
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• 2005

Polyhydroxyalkanoates (PHAs) are homo or hetero polyesters of (R)-hydroxyalkanoates accumulated in various microorganisms under growth-limiting condition in the presence of excess carbon source. They have been suggested as biodegradable substitutes for chemically synthesized polymers. Recombinant Escherichia coli is one of the promising host strains for the economical production of PHAs, and has been extensively investigated for the process development. The heterologous PHA biosynthetic pathways have been established through the metabolic engineering and inherent metabolic pathways of E. coli have been redirected to supply PHA precursors. Fermentation strategies for cultivating these recombinant E. coli strains have also been developed for the efficient production of PHAs. Nowadays, short-chain-length (SCL) PHAs are being re-invited due to its improved mechanical properties and possible applications in the biomedical area. In this article, recent advances in the development of metabolically engineered E. coli strains for the enhanced production of SCL-PHAs are reviewed. Also, medical applications of SCL-PHAs are discussed.