• 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)

• Fibers and Polymers
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• v.6 no.2
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• pp.113-120
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• 2005

Helium-oxygen plasma treatments were conducted to modify poly(trimethylene terephthalate) (PIT) and poly(ethylene terephthalate) (PET) warp knitted fabrics under atmospheric pressure. Lubricant and contamination removals by plasma etching effect were examined by weight loss $(\%)$ measurements and scanning electron microscopy (SEM) analysis. Surface oxidation by plasma treatments was revealed by x-ray photoelectron spectroscopy (XPS) analyses, resulting in formation of hydrophilic groups and moisture regain $(\%)$ enhancement. Low-stress mechanical properties (evaluated by Kawabata evaluation system) and bulk properties (air permeability and bust strength) were enhanced by plasma treatment. Increasing interfiber and interyarn frictions might play important roles in enhancing surface property changes by plasma etching effect, and then changing low-stress mechanical properties and bulk properties for both fabrics.

• Textile Coloration and Finishing
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• v.2 no.4
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• pp.223-230
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• 1990

This study was carried out with the view of fundamental investigating to improve the tactile and the hygroscopicity of Poly (ethylene terephthalate) (PET) fibers. Mono-sodium ethylene glycolate in ethylene glycol (MSEG-EG) solution was prepared and PET films were treated with it. The following conclusions were obtained. 1. The tensile strength decreased with increasing decomposition ratio while density, crystallinity and crystallite size increased with increasing decomposition ratio when PET films were treated with MSEG-EG solution. 2. Number of carboxyl end groups was increased until 10-20% decomposition ratio when PET films were treated with MSEG-EG solution. However, the decomposition ratio became more than 20%, the number of carboxyl end groups had tendency to decreased. 3. The surface tension of PET films increased for treating with MSEC-EG solution. Hydrogen bonding force and poler force among the components of surface tension increased while dispersion force among those decreased. 4. The moisture region of PET films increased with increasing decomposition ratio when PET films were treated with MSEG-EG solution.

• Proceedings of the Korean Fiber Society Conference
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• 2000.04a
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• pp.89-92
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• 2000

• Macromolecular Research
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• v.15 no.2
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• pp.178-184
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• 2007

A poly(ethylene terephthalate) (PET)/organosilicate nanocomposite, with enhanced mechanical properties, has been prepared using the melt intercalation method. For this purpose, a new organic modifier has been synthesized for the preparation of organosilicate, which is thermally stable and compatible with PET. The use of the new organosilicate yielded almost exfoliated PET nanocomposite; whereas, the PET nanocomposites prepared by use of commercial organoclays (Cloisite 15A and 30B) show only an intercalated morphology. Particularly, the use of the new organosilicate showed an enhanced tensile modulus, and without sacrifice of the tensile strength and elongation on breaking, while the use of commercial organoclays only exhibit a trade-off between those mechanical properties.

• Carbon letters
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• v.13 no.1
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• pp.51-55
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• 2012

In this work, expanded graphite (EG)-reinforced poly(ethylene terephthalate) (PET) nanocomposites were prepared by the melt mixing method and the content of the EG was fixed as 2 wt%. The effect of multi-walled carbon nanotubes (MWCNTs) as a co-carbon filler on the electrical and mechanical properties of the EG/PET was investigated. The results showed that the electrical and mechanical properties of the EG/PET were significantly increased with the addition of MWCNTs, showing an improvement over those of PET prepared with EG alone. This was most likely caused by the interconnections in the MWCNTs between the EG layers in the PET matrix. It was found that the addition of the MWCNTs into EG/PET led to dense conductive networks for easy electron transfers, indicating a bridge effect of the MWCNTs.

• Macromolecular Research
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• v.12 no.1
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• pp.85-93
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• 2004

We have prepared poly(ethylene terephthalate) (PET) nanocomposites filled with two different types of fumed silicas, hydrophilic (FS) and hydrophobic (MFS) silicas of 7-nm diameter, by in situ polymerization. We then investigated the morphological changes, rheological properties, crystallization behavior, and mechanical properties of the PET nanocomposites. Transmission electron microscopy (TEM) images indicate that the dispersibility of the fumed silica was improved effectively by in situ polymerization; in particular, MFS had better dispersibility than FS on the non-polar PET polymer. The crystallization behavior of the nanocomposites revealed a peculiar tendency: all the fillers acted as retarding agents for the crystallization of the PET nanocomposites. The incorporation of fumed silicas increased the intrinsic viscosities (IV) of the PET matrix, and the strong particleparticle interactions of the filler led to an increased melt viscosity. Additionally, the mechanical properties, toughness, and modules of the nano-composites all increased, even at low filler content.

• Polymer(Korea)
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• v.30 no.2
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• pp.118-123
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• 2006

The effect of transesterification on the rheological properties in the melt reactive blending of poly(butylene terephthalate)(PBT) with poly(ethylene terephthalate)(PET) has been studied. The melt viscosity depression in PBT was found in PBT/PET blends due to the intrinsic low melt viscosity of PET compared to PBT. In addition, the thermal degradation in the melt blending and transesterification between two polyesters were considered as other factors fer the lowering of the melt viscosity in the blends. In the PBT/PET blends, calcium stearate was less effective than in PBT as a lubricant, however it accelerated both the thermal degradation and transesterification during melt blending. As a result, further melt viscosity drop was obtained in the reactive melt blending of PBT/PET.

• Fibers and Polymers
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• v.2 no.3
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• pp.129-134
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• 2001

Liquid crystalline (LC) poly(ethylene terephthalate-co-2(3)-chloro-1,4-phenylene terephthalate) (50/50, mole/mole) [PECPT] was synthesized and blended with polycarbonate (PC). LC properties of PECPT and thermal, morphological, and rheological behaviors of the PECPT/PC blend were studied. PECPT showed the nematic LC phase and much longer relaxation time than poly(ethylene terephthalate) (PET). The apparent melt viscosity of PECPT was one third of that of FET. An abrupt torque change was observed during the blending process due to the orientation of LC domains. For the blends containing 10~30 wt% of PECPT, the complex viscosities were higher than that of PC. As PECPT content increases above 40 wt%, shear thinning was observed. The lowest complex viscosity was obtained at 40~50 wt%. Transesterification of PECPT and PC was confirmed by the selective chemical degradation of carbonate groups in PC.

• Macromolecular Research
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• v.10 no.1
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• pp.44-48
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• 2002

The supermolecular structures of poly(ethylene terephthalate) (PET), poly(ethylene 2,6-naphthalate) (PEN), and their blend were investigated with optical microscopy and small angle light scattering. With increasing the crystallization temperature, incomplete spherulitic texture was developed for the PET samples. At a high crystallization temperature of 220 $^{\circ}C$, the light scattering pattern represented a random collection of uncorrelated lamellae. The general morphological appearances for the PEN samples were similar to that of the PET. A notable feature was that the spherulites of the PEN formed at 200 $^{\circ}C$ showed regular concentric bands arising from a regular twist in the radiating lamellae. The spherulitic morphology of the PET/PEN blend was largely influenced by the changes of the sequence distribution in polymer chains determined by the level of transesterifcation. The increased sequential irregularity in the polymer chains via transesterification caused a morphological transition from a regular folded crystallite to a tilted lamellar crystallite.