• Polymer(Korea)
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• v.33 no.3
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• pp.198-202
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• 2009

Oligo(ethylene terephthalate)(OET), oligo(ethylene succinate-co-terephthalate)(OEST) and oligo(butylene succinate-co-terephthalate)(OBST), which are part of the poly(ethylene terephthalate)(PET) oligomer, were synthesized. Degradation test of oligomers carried out by the presence of lipase PS. There were two objectives in the experiment: first, to measure the weight remaining of the PET oligomer as increasing degradation time, and second to examine the degradation mechanism by analyzing the resulting degraded product. In the synthesis of OEST and OBST, by controlling the feed ratio of both OEST and OBST, we were able to obtain oligomer of different composition ratios. The various composition ratios resulted in oligomer of vastly different thermal properties. We observed that both OEST and OBST were degraded using lipase PS, but as the composition of terephthalic acid was increased, the lipase PS became less effective. We confirmed that the lipase PS easily decomposed polyester of the aliphatic compound.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.213-214
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• 2003

1950년 Poly(ethylene terephthalate)(이하 PET)의 상업화 이후 Poly(trimethylene terephthalate)(이하 PTT)는 동종의 Poly(methylene terephthalate)계열의 고분자 중에서 Poly(butylene terephthalate) (이하 PBT)와 함께 최근 가장 주목받는 섬유 중의 하나이다. PTT 섬유는 얼마 전까지만 해도 주원료인 1,3-propanediol(이하 PDO)의 가격이 너무 높아 지난 60년 간 상업화 및 학문적 연구가 거의 이루어지지 않다가 최근 미국의 Shell사와 독일의 Degussa(미국의 Dupont)에 의해 PDO가 대량 생산되면서 상업화에 대한 연구가 활발히 이루어지고 있다. (중략)

• Korean Chemical Engineering Research
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• v.51 no.1
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• pp.58-67
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• 2013

PBT (polybutylene terephthalate) has excellent mechanical properties such as low absorption, dimensional stability, abrasion resistance. It is used in manufacturing electronic components, the automobile part and the various precise parts. Bis (hydroxybutyl) terephthalate (BHBT) which is a PBT monomer, can be produced by transesterification reaction of DMT (dimethyl terephthalate) with 1,4-butandiol (BD). The kinetics of transesterification reaction of DMT with BD using zinc acetate as a catalyst was studied in a batch reactor. Previous kinetic studies was carried out in a semibatch reactor where generated methanol was removed so that reverse reactions were not considered in the kinetic expressions, resulting in inaccuracy of the kinetic model. Mathematical models of a batch reactor for the transesterification reaction were developed and used to characterize the reaction kinetics and the composition distribution of the reaction products. More accurate models than previous models was obtained and found to have a good agreement between model predictions and experimental data.

• Korean Chemical Engineering Research
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• v.51 no.1
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• pp.144-150
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• 2013

The kinetics of the transesterification of dimethyl terephthalate (DMT) with ethylene glycol (EG) was studied in a batch reactor. Bishydroxyethyl terephthalate (BHET), which is poly(ethylene terephthalate) (PET) monomer, can be produced by the transesterification reaction. Zinc acetate was used as a catalyst. Previous kinetic studies was carried out in a semi-batch reactor where generated methanol was removed so that reverse reactions were not considered in the kinetic expressions, resulting in inaccuracy of the kinetic model. Mathematical models of a batch reactor for the tranesterification reaction were developed and used to characterize the reaction kinetics and the composition distribution of the reaction products. More accurate models than previous ones were obtained and found to have a good agreement between model predictions and experimental data. Effect of process variables on the esterification reaction was investigated based on the experimental and simulation results.

• Korean Journal of Chemical Engineering
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• v.35 no.12
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• pp.2464-2467
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• 2018

Organic batteries are attractive alternatives to conventional inorganic batteries because of their low cost, biodegradation, and renewability, and their consequent environmental friendliness. We investigated the influence of carbon conductors and electrolytes in organic batteries using dilithium terephthalate ($Li_2C_8H_4O_4$). The synthesized dilithium terephthalate has well-grown crystallinity and non-uniform shaped particles without impurities. The dilithium terephthalate-based battery shows good electrochemical properties with a LiTFSI/TEGDME electrolyte and graphene as the carbon conductor in an organic electrode. The results are ascribed to the high lithium transference number of LiTFSI/TEGDME and the high electrical conductivity of graphene.

• Clean Technology
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• v.13 no.3
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• pp.173-179
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• 2007

In this study the amount of equilibrium sorption of C.I. Disperse Yellow 54 dye in the polymeric textiles such as PTT (poly(trimethylene terephthalate)) and PET (poly(ethylene terephthalate)) textiles was measured in the presence of supercritical carbon dioxide at different temperatures, pressures, and time. The amount of dye sorption increased with temperature and pressure in both PTT and PET textiles, but the increasing rate decreased with pressure. The PTT textile has much larger dye sorption than PET textile. The increasing rate of dye sorption decreased with time at same temperature and pressure for both PTT and PET textiles.

• Macromolecular Research
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• v.12 no.5
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• pp.459-465
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• 2004

We have synthesized poly(l,4-cyclohexylenedimethylene terephthalate-co-hexamethylene terephthalate) [P(CT-co-HT)] random copolymers having various comonomer contents, from 0 to 100 mol% HT, by melt-condensation and have investigated their crystallization behavior by using differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD). We observed that P(CT-co-HT)s exhibit clear melting and crystallization peaks in their DSC thermograms and sharp diffraction peaks in their WAXD patterns for all of their copolymer compositions as a result of cocrystallization of the CT and HT units, even though the copolymers are statistically random copolymers. When we plotted the melting and crystallization temperatures of P(CT-co-HT)s and the d-spacings of all the reflections against the copolymer composition, we observed a eutectic point at ca. 80 mol% HT, which suggests that a crystal transition occured from a PCT-type crystal to a PHT-type crystal. Both the DSC and WAXD results support the notion that P(CT-co-HT) copolymers undergo an isodimorphic cocrystallization.

• Journal of the Semiconductor & Display Technology
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• v.21 no.2
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• pp.7-10
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• 2022

A functional polyethylene terephthalate substrate to increase light extraction efficiency of organic light-emitting diodes is studied. We formed nano-structured PET surfaces by controlling the power, gas, and exposure time of the linear ion-beam. The haze of the polyethylene terephthalate can be controlled from 0.2% to 76.0% by changing the peak-to-valley roughness of nano structure by adjusting the exposure cycle. The treated polyethylene terephthalate shows average haze of 76.0%, average total transmittance of 86.6%. The functional PET increases the current efficiency of organic light-emitting diodes by 47% compared to that of organic light-emitting diode on bare polyethylene terephthalate. In addition to polyethylene terephthalate with light extraction performance, by conducting additional research on the development of functional PET with anti-reflection and barrier performance, it will be possible to develop flexible substrates suitable for organic light-emitting diodes lighting and transparent flexible displays.

• Polymer(Korea)
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• v.24 no.1
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• pp.16-22
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• 2000

Poly(butylene terephthalate- co-oxybenzoate)(PBOT) containing mesogenic oxybenzoate units in the main chain was synthesized through ester exchange reaction by melt mixing of poly(butylene terephthalate)(PBT) and p-acetoxybenzoic acid (ABA). From the kinetics of the copolymerization reaction, the activation energies and the rate constants of homopolymerization and copolymerization, k$_{h}$ and k$_{c}$, could be determined. From the reaction conditions of different compositions, 4/6, 5/5, and 6/4 of PBT/ABA, at 250, 260, and 27$0^{\circ}C$, it was revealed that copolymerization between PBT and ABA proceeds on a pseudo-second order reaction if the ABA content and its conversion are low. In this case, the ratio of rate constants of homopolymerization to copolymerization was in the range from 1.08 to 3.17, indicating that the copolymer with more notable block character was obtained at the higher mole fraction of ABA and at higher temperature.e.e.

• Proceedings of the Korean Fiber Society Conference
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• 1986.06a
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• pp.11-11
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• 1986