• Korean Journal of Materials Research
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• v.19 no.1
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• pp.1-6
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• 2009

In this study, the stress-strain response and the cracking behaviors of ITO film on a PET substrate are investigated. The cracking behaviors of ITO thin films deposited on a thermoplastic semi-crystalline polymer developed for flexible display applications was investigated by means of tensile experiments equipped with an electrical measurement apparatus and an in-situ optical microscope. Electrical resistance increased gradually in the elastic-to-plastic transition region of the stress strain curves and cracks formed. Numerous cracks were found in this region, and the increase of the resistance was linked to the cracking of ITO thin films. Upon loading, the initial cracks perpendicular to the tensile axis were observed at about 1% of the total strain. They propagated to the entire sample width as the strain increased. The spacing between the horizontal cracks is thought to be determined by the fracture strength and the thickness of the ITO film as well as by the interfacial strength between the ITO and PET. The effect of the strain rate on the cracking behavior was also investigated. The crack density increased as the strain increased. The spacing between the horizontal cracks (perpendicular to the stress axis) increased as the strain rate decreased. The increase of the crack density as the strain rate decreased can be attributed to the higher fraction of the plastic strain to the total strain at a given total strain. The higher critical strain for the onset of the increase in the resistance and the crack initiation of the ITO/PET with a thinner ITO film (300 ohms/sq.) suggests a higher strength of the thinner ITO film.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2399-2401
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• 1999

This paper indicate that phase resolved partial discharge pattern are investigated on PET films with semiconductor particle. In this study, we measured phase-resolved PD pattern and statistical parameter from PET specimens according to containing semiconductor particle. Measurement system is the conventional PD detector using digital signal processing technique. The relationship of semiconductor particle in PET film was discussed through the difference of $\psi$-q-n distribution and statistical analysis.

• Macromolecular Research
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• v.11 no.5
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• pp.387-392
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• 2003

The ablation effects of Ar-plasma treatment and alkali-decomposition behavior in NaOH solution of polyethylene terephthalate (PET) film were investigated. The modifications were evaluated by analysis of atomic force microscopy topographical changes, and by the measurement of decomposition yield in conjunction with heats of formation and electron densities of acyl carbon calculated by Parameterization Method 3 method. It has shown that the alkali-decomposition is hampered by plasma treatment and its decomposition yield is closely related with plasma treatment conditions such as exposure time to plasma. Plasma-treated PET films exhibited lower decomposition yield, compared to that of virgin PET. Increasing plasma exposure time contributes positively to decrease the decomposition yield. It has also shown that the topography of PET surface was affected by the base-promoted hydrolysis as well as Ar-plasma treatments. These behaviors are attributed to the decreased nucleophilicity of acyl carbon damaged by the ablation of Ar-plasma.

• Textile Coloration and Finishing
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• v.15 no.3
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• pp.185-191
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• 2003

Surface modification of poly(ethylene terephthalate) (PEI) films by treatment with ethoxylated alkylaminoanthraquinoes which was synthesized by the reaction of 1-aminoanthraquinone with poly(ethylene glycol) via a series of methylene spacer were investigated. The synthesized ethoxylated alkylaminoanthraquinones showed definite cloud point as in nonionic surfactants, and the adsorption of the compounds on PET increased near the cloud point. At same temperature the adsorption increased with the length of methylene spacer; hexyl-octyl-, and decyl-. The adsorption was limited to the extreme surface of PET film, which made the surface of PET film hydrophillic by reducing water contact angle.

• Journal of the Semiconductor & Display Technology
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• v.8 no.2
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• pp.49-53
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• 2009

The oxygen barrier films were formed on poly(ethylene terephthalate) (PET) substrate by a sol-gel process using 3-aminoproprytrimethoxysilane (APTMOS). The effects of solvent type, coating times and incorporation of fumed silica on oxygen permeability coefficient were investigated. The APTMOS coating film prepared from methanol as a solvent exhibited higher oxygen barrier properties than that using THF. The oxygen permeability coefficient of coated film with APTMOS/methanol by coating 7 times was measured to be $2.28{\times}10^{-6}$, while that of PET film was $1.16{\times}10^{-4}$ GPU. The addition of fumed silica does not affect the oxygen barrier properties. It may be explained that silica particles disrupt chain packing, which leads to an increase in free volume for permeation.

• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.1043-1047
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• 2002

This study was carried out to investigate the effect of packaging materials (Ny/PE, PET/Al/PE, PET/PE/LDPE/CPP, PET/Al/Ny/CPP films, and bottle) and packaging methods (atmosphere and vacuum) on the physicochemical properties of Onion Kimchi and Rosemary-onion Kimchi stored at $5^{\circ}C$. Reducing sugar contents and pHs of Onion Kimchi and Rosemary-onion Kimchi decreased, whereas levels of titratible acidity and vit C contents increased with increasing the storage time. The fermentation of Rosemary-onion Kimchi was slower than that of Onion Kimchi. PET/PE/LDPE/CPP film was the most effective for Onion Kimchi packaging among all packaging materials tested.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.24 no.2
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• pp.41-48
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• 2018

A printable time temperature integrator (TTI) consisting of oxygen indicator and cover films with various oxygen permeability was developed. The printing ink contained methylene blue (oxygen indicator) which changed in color during storage. $TiO_2$ and glycerol for UV-activation of TTI and zein and ethanol for printing performance were also contained in the printing ink. The cover film on the ink was employed to control the color change rate and temperature dependency (Arrhenius activation energy, $E_a$) by using the different films (PE, PET, OPP, and LLDPE). The film properties were varied by annealing. TTI was produced by silk screen printing. As a result, the color change rates were different for the cover films, being the highest in TTI with LLDPE, followed by OPP, PE, and PET. The rate decreased with increase in the cover film thickness. The $E_a$ was the highest in TTI with LLDPE, followed by OPP, PE, and PET. The $E_a$ did not change with the cover film thickness. The annealed PVC and PET film were lower in oxygen permeability than the unannealed ones, indicating the lower color change rate.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.595-605
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• 2018

In recent years, researches on organic-inorganic coating films have conducted a nanocomposite system composed of organic resin matrices having excellent flexibility and chemical stability and inorganic materials having excellent mechanical properties. The o-phenylphenoxyethyl acrylate (OPPEA) used as the acrylate monomer has a high refractive index of 1.58, and the bisphenol A ethoxylate diacrylate (BAEDA) has a low refractive index but improves the chemical stability of the organic resin. In addition, zirconia used as an inorganic material exhibits excellent durability and optical properties. In this study, the BAEDA contents in acrylate monomer were controlled to produce a film with suitable optical transparency. And optimum conditions were established by comparing the changes in surface properties of PET films detected with pencil hardness tester, Abbe's refractometer, and UV-vis spectrophotometer. The hydrophobicity and the dispersibility of zirconia in acrylate monomer were much improved after modification with ${\gamma}$-methacryloxypropyltrimethoxysilane (MPS), which is a silane coupling agent. And the existence of ester C=O bond peak at $1716cm^{-1}$ introduced by MPS through FT-IR ATR spectrophotometer confirmed the completion of surface modification of zirconia with MPS. In addition, the presence of silicon atom on the surface modified zirconia was also proved using X-ray fluorescence spectrometer. When the photocurable hybrid coating was prepared by introducing chemically modified zirconia into acrylate monomer, the refractive index of this coated PET film was improved by 1.2%, compared to the only acrylate coated PET film. The homogeneous distribution of zirconia in acrylate coating layer on PET film was also identified through SEM/EDS mapping analysis technique.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.24 no.6
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• pp.252-255
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• 2014

Indium tin oxide (ITO) films with various oxygen partial pressure from 0 to $6{\times}10^{-5}$ Pa were prepared onto polyethylene terephthalate (PET) using RF magnetron sputtering at room temperature. The structural, electrical and optical properties of the grown ITO films were investigated as a function of the oxygen partial pressure. The amorphous nature of the ITO films was dominant at the partial pressure below $1{\times}10^{-5}$ Pa and the degree of crystallinity increased as the oxygen concentration increased further. This structural change comes with the increased carrier concentration and reduction of the electrical resistivity down to $9.8{\times}10^{-4}{\Omega}{\cdot}cm$. The average transmittance (at 400~800 nm) of the ITO deposited on the PET substrates increased as the oxygen partial pressure increased and transmittance above 80 % was achieved with the partial pressure of $4{\times}10^{-5}$ Pa. The results show that the choice of optimal oxygen partial pressure can present improved film crystallinity, the increased carrier concentration, and the enhancement in the electrical conductivity.

• Journal of Bio-Environment Control
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• v.10 no.3
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• pp.141-147
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• 2001

To compare to the optical and physical properties of covering materials for plastic greenhouse, EVA(ethylene vinyl acetate, 0.08 mm), polyorefine antifog (0.1 mm), fluoric (0.06 mm), diffused (0.15 mm), polyorefine antidrop (0.15 mm) and PET (polyethylene terephthalate, 0.5 mm) films were used. The small greenhouse (5.4$\times$18.5$\times$2.9 m, W$\times$L$\times$H) investigated during 3 years form 1997 to 1999. After covering materials were used for greenhouse covering during 30 months, UV (300-400 nm) transmittances of diffused film and PET were appeared from 25 to 26%, while those of fluoric film and the other films were 76% and from 63 to 67%. For PAR (photosynthetically active radiation, 400-700 nm), the transmittances of fluoric, antidrop, PET, antifog, EVA, and diffused film were 86.5%, 80.5%, 76.3%, 75.5%, 74.1% and 61.9% respectively. The losses of PAR transmittance of EVA and the antidrop film during period between 7 days and 30 months were higher value 12% and lower value 6% than any other film. Under the canopy of tomato plants, light intensities of the diffused film and the antifog film were 2.5 times and 1.4 times higher than those of PET. Tensile resistances of fluoric film at the break point were the higher than those of antifog film and diffused film. While impact resistance of the antidrop film was the highest value, but the fluoric film was the lowest. Air temperature inside the greenhouse for the day showed to be changed the similar light transmittance of the films. But the increasing order of air temperature for the night was PET, fluoric, antidrop, diffused, antifog and EVA film. Especially, air temperature in the PET was 4$^{\circ}C$ higher than that in the EVA. Solar radiations of the fluoric film, the antidrop film, PET and antifog film in the greenhouse were 32%, 15%, 11% and 4% higher than those of PET. However, those of the diffused film was 7% less than PET.