• Journal of the Korean Chemical Society
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• v.32 no.3
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• pp.276-284
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• 1988

The crystallization behaviours of poly(ethylene terephthalate) modified by 1, 3-propane diol, 1, 5-pentane diol, 1, 6-hexane diol, or poly(ethylene glycol) of molecular weight 300 as a third component were studied by isothermal and nonisothermal crystallization. When the content of the third diol was about 4 mol %, the isothermal crystallization rate at the same supercooling below the melting temperature and the nonisothermal crystallization rate at the same overheating above the glass transition temperature were increased more by the shorter flexible diol unit. On the contrary the nonisothermal crystallization rate at the same supercooling below the melting temperature was increased more by the longer flexible diol unit.

• Polymer(Korea)
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• v.38 no.2
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• pp.240-249
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• 2014

Multi-walled carbon nanotube (MWNT) reinforced poly(ethylene terephthalate) (PET) composites are studied. To increase the interfacial interactions between PET and MWNTs, the MWNTs are functionalized with bishydroxy-ethylene-terephthalate (BHET). The functionalized MWNTs are melt blended into PET matrix using a twin screw extruder. The amount of MWNTs loaded in PET matrix ranges from 0.5 to 2.0 wt%. After compounding and spinning, the filaments are post-drawn and annealed. To verify the chemical modifications of carbon nanotubes, Raman, $^1H$ NMR, XPS, TGA and FE-SEM are used. The nanocomposites are also analyzed with DSC, TGA, and UTM. These tests show that crystallization temperature and thermal degradation temperature increase due to the functionalized MWNTs. Also, tensile test shows that yield strength and toughness increase more than 30% with addition of only 1 wt% of MWNTs. These results show that the introduction of BHET onto the MWNTs is a very effective way in manufacturing MWNT/PET composite.

• Korean Chemical Engineering Research
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• v.53 no.2
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• pp.253-261
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• 2015

The kinetics of the transesterification of dimethyl terephthalate (DMT) with diethylene glycol (DEG) was studied in a batch reactor. bis-hydroxyethoxytethyl-terephthalate (BHEET), which is polyester polyol 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, which took the reverse reaction into account, 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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3351-3356
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• 2014

Recently, Importance of studying based on biomass materials have increased due to the concern about plastic waste problems. Cellulose acetate butyrate (CAB) is a potential alternative to petroleum-based plastics because of its biodegradable property. Poly(ethylene-co-isosorbide terephthalate) (PEIT) is bio-based plastic, produced by isosorbide monomer. In this study, CAB/PEIT blends were prepared by solution blending to improve thermal stability of CAB. CAB and PEIT were dissolved in chloroform, and then precipitated in ethanol. To evaluate the compatibility of CAB/PEIT blends, the morphology and glass transition behaviors were analyzed by FE-SEM and DMA, respectively. TGA results revealed the improved thermal stabilities of the PEIT-rich and 50:50 compositions. No new or changed crystal structures were observed in the XRD result. Finally, CAB/PEIT solution blends showed good compatibility in overall compositions.

• Polymer(Korea)
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• v.33 no.2
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• pp.164-168
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• 2009

The effects of chemically modified thermoplastic starch (CMPS) on the morphology, thermal and mechanical properties of the blends of poly (lactic acid)(PLA) and poly(butylene adipate-co-terephthalate)(PBAT) were studied. Blends of PLA/PBAT with the CMPS contents of 10, 20 and 30 wt% on the basis of PLA/PBAT weight were prepared by a twin screw extruder. The morphology, thermal and mechanical properties of the blends were examined by using scanning electron microscope (SEM), differential scanning calorimeter (DSC) and a tensile tester. The DSC study revealed that PLA/PBAT blends are thermodynamically immiscible, while the compatibility was much improved by addition of the CMPS.

• Journal of the Korean Electrochemical Society
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• v.22 no.3
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• pp.122-127
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• 2019

In this study, we investigate the electrochemical performance of lithium terephthalate (LTA) battery using graphite coated metal current collector to overcome the disadvantages of organic batteries which is high interfacial resistance between current collector and electrode. The LTA anode material is synthesized by acid-based ion exchange reaction without impurities. The contact properties between stick-type LTA-based electrode and graphite coated current collector are estimated by the cross-section SEM and EIS. The graphite coated current collector significantly reduced the interfacial resistance of the LTA battery. The second discharge capacities of bare current collector LTA and graphite coated current collector LTA batteries are 107.6 mAh/g and 148.8 mAh/g at 0.1C, respectively. The graphite coated current collector LTA batteries show higher cycle life, higher discharge capacity, and higher rate-capability than bare LTA batteries.

• Textile Coloration and Finishing
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• v.13 no.3
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• pp.197-202
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• 2001

The mechanical properties and dyeability of Poly(trimethylene terephthalate)(PTT) were investigated and compared to PET. Glass transition temperature of PTT was lower than that of PET, because amorphous region of PTT is mote flexible. n has smaller molecular and specific stress and larger strain than those of PET, due to the difference of molecular structure. Dyeing transition temperature of PTT was lower by $20^\circ{C}$ than that of PET. Because PTT has flexible chain and zigzag structure, dyeing Fate of PTT is faster than PET and dyeing of PTT is begun at lower temperature. As the hydrophobicity of disperse dyes increased, the ratio of equilibrium dye uptake on PTT to that on PET was increased.

• Journal of the Korean Society of Industry Convergence
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• v.9 no.4
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• pp.337-341
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• 2006

The tensile properties of Poly(trimethylene terephthalate, PTT) $1{\times}1Rib$ knitted fabrics were experimentally studies, and the specimens has $1{\times}1$ rib stitched structure which are weft knitted fabrics with various lengths of loop. The $1{\times}1$ rib weft knitted fabric showed larger tensile linearity, tensile energy and tensile resilience in the direction of courses. The tensile properties increased with increasing the loop density in all directions, and perfectly increased with the course directions than the wale directions.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.10 no.3
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• pp.78-85
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• 1996

This paper experience the mechanism for the electret of polyethyleneterephthalate(PET) by using surface potentail measurement means. We investigated the internal charge production and becoming week by evaporating electrode in sample structure of electret coexist with hetero charge and homo charge, as the study based on two charge theory. We expects that the hetero charge consists of the dipole and ion displacement of internality, the homo charge consists of injected charge of externality.

• Environmental Engineering Research
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• v.11 no.5
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• pp.250-256
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• 2006

The combustion kinetics of poly(ethylene terephthalate) (PET) was studied by the dynamic model which accounts for the thermal decomposition of polymer at any time. The kinetic analysis was performed by a conventional nonisothermal thermogravimetric (TG) technique at several heating rates between 10 and 40 K/min in air atmosphere. The thermal decomposition of PET in air atmosphere was found to be a complex process composed of at least two stages for which kinetic values can be calculated. The combustion kinetic analysis of PET gave apparent activation energy for the first stage of $257.3{\sim}269.9\;kJ/mol$, with a value of $140.5{\sim}213.8\;kJ/mol$ for the second stage. To verify the effectiveness of the kinetic analysis method used in this work, the kinetic analysis results were compared with those of various analytical methods. The kinetic parameters were also compared with values of the pyrolysis of PET in nitrogen atmosphere.