• Textile Coloration and Finishing
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• v.16 no.1
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• pp.18-25
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• 2004

In this study, the effect of microwave which can increase temperature rapidly on polyester alkaline dyeing was investigated. The final K/S values of polyester fabrics dyed by microwave lower than those of atmospheric dyeing because of the evaporation loss of dyeing solution. If the dyeing time makes longer as much as that in atmospheric dyeing, the K/S values of polyester fabrics dyed under microwave were similar to those of atmospheric dyeing. The K/S values of polyester fabrics dyed in pH 9.5 were higher than those in pH 5.5 in case of aliphatic carriers. The K/S values of organic reagent pretreated polyester fabrics dyed by use of aromatic carriers were not higher than those of non-treated polyester fabrics. But the K/S values of polyester fabrics dyed by use of aliphatic carriers were higher than those of non-treated polyester fabrics. The tensile strength were decreased with increasing of dyebath pH because the polyester fabrics were easily decomposed by high alkali.

• Proceedings of the Korean Fiber Society Conference
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• 1997.04a
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• pp.328-332
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• 1997

Hot stretching focused on the improvement of properties of poly(L-lactic acid) fiber. Some aliphatic polyesters are biodegradable under microbial attack and the new unique applications are expected. Generally, these materials have a somewhat low melting temperature and low mechanical properties compared with the aromatic polyesters. In this study, melt-spinning of poly(L-lactic acid) was conducted. We investigated effects of the stretching and the molecular orientation of aliphatic polyester fibers on the change of fine-structure. Glass transition temperature, molecular orientation and crystallinity increased according to the increase of stretching ratio.

• Polymer(Korea)
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• v.24 no.3
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• pp.358-365
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• 2000

Miscibility itnd thermal behavior of blends of synthetic biodegradable aliphatic polyester (Bionolle) with poly(epichlorohydrin) (PECH) were investigated by a differential scanning calorimetry (DSC), a dynamic mechanical thermal analyzer (DMTA) and a rotational rheometer. Observed both single glass transition temperatures from the DSC in agreement with the Fox equation and single T$_{g}$ changes as a function of composition from the DMTA indicate that these blend mixtures are miscible. In addition, the miscibility of this blend system was also observed from the single curve of the Cole-Cole Plot of log G′($\omega$) vs. log C"($\omega$) from the dynamic test using a rotational rheometer. This was further verified from the cryogenically fractured surface of BDP/PECH blends by scanning electron microscopy.

• Polymer(Korea)
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• v.34 no.5
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• pp.424-429
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• 2010

The hybrid composites of aliphatic polyester-silica were prepared via a sol-gel reaction and their potential application using as a buffer coating layer in the thermoelectric device were investigated. When aliphatic polyesters were thermally treated at a high temperature of $240^{\circ}C$, the polymer showed an increases in thermal degradation temperature by $30{\sim}90^{\circ}C$ according to the thermal treatment time. The polyester-silica composites showed an increases in thermal degradation temperature by $30{\sim}50^{\circ}C$ according to the content of the added silica. Polyester-silica composite showed neither discoloration nor change in optical properties because Knoevenagel condensation reaction was hindered by silica structure. The thermal conductivity of the composites increased linearly according to the content of added silica.

• Elastomers and Composites
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• v.46 no.2
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• pp.158-163
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• 2011

Rigid polyurethane foam (PUF) was synthesized with different contents of aliphatic polyester polyol, aromatic polyester polyol and aliphatic polyether polyol to know change of properties under sea water. UTM(universal testing machine), DSC(differential scanning calorimetry), hardness meter and FT-IR(Fourier transform spectroscopy) were used to study the PUF`s physical properties under sea water. Compressive strength and hardness of PUF decreased with increasing the content of aromatic polyester polyol under sea water as aging. According to the results of IR spectral analysis, reduction of urethane and urea peak was found and allophanate and biuret peak increased. Although glass transition temperature of PUF increased, mechanical properties of PUF decreased under sea water, because PUF gets brittle when crosslink density increase.

• Proceedings of the Korean Fiber Society Conference
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• 1992.06a
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• pp.47-47
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• 1992

• Polymer Science and Technology
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• v.5 no.1
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• pp.13-18
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• 1994

• Macromolecular Research
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• v.14 no.2
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• pp.179-186
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• 2006

In the present work, low density polyethylene (LDPE)/aliphatic polyester (APES)/organoclay ternary nanocomposites were prepared. In particular, the effect of a compatibilizer, polyethylene-graft-maleic anhydride (PE-g-MAH), on the morphology and properties of the ternary nanocomposites was investigated. LDPE/APES/organoclay nanocomposites were prepared through melt intercalation method using two different kinds of organoclay. The dispersibility of silicate clays in the nanocomposites was investigated by X-ray diffraction and atomic force microscopy. The ternary nanocomposites showed higher tensile properties than the LDPE/APES blend did. The dispersibility and properties of nanocomposites containing Cloisite 30B were better than those of the nanocomposites containing Cloisite 20A. Unlike Cloisite 20A, hydroxyl groups in the intercalants in Cloisite 30B interlayer underwent a certain polar interaction with the carboxyl group of APES, favoring the intercalation of APES chains and the formation of LDPE/APES/Closite 30B nanocomposites. However, the introduction of the polar hydroxyl groups also enhanced the interaction with the silicate surface at the same time, thereby rendering somewhat difficult the replacement of the surface contacts by LDPE chains, and impeding the extensive intercalation and further exfoliation of Cloisite 30B in the LDPE/APES matrix. The compatibilizer enhanced the intercalation of the polymer chain inside the clay gallery and thus improved the mechanical properties of the ternary nanocomposites. Rheological measurements of the nanocomposites via frequency sweep experiment indicated a certain interaction between the clay platelet and the polymer molecules in the melted state.

• Polymer(Korea)
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• v.24 no.2
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• pp.281-286
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• 2000

A series of amorphous polyesters were synthesized from amorphous polyether and sebacoyl chloride. The structure and competition of the obtained aliphatic polyester were confirmed by $^1$H-NMR and FT-IR. The number average molecular weights (M$_{n}$) of the obtained polymer were ranging from 8000 ~ 15000. These polyesters showed no crystallinity and their glass transition temperatures (T$_{g}$) were around -77$^{\circ}C$. For comparison, aliphatic polyesters were also synthesized from poly(ethylene glycol) (PEG) with M$_{n}$ of 200, 400, and 1000. As the M$_{n}$ of PEG increased, the melting point of the obtained polyester increased, and the crystallinity of the obtained polyester increased showing 8.8%, 16.2%, and 46.7%, respectively.ively.y.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2560-2566
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• 2012

The present study investigates how the thermal stability of retinol (vitamin A) encapsulated in polyester nanoparticles is influenced by the types of polyester used for the nanoparticles. A variety of polyester-retinol nanoparticles were prepared with various polyesters like: poly(ethylene adipate), PEA; poly(butylene adipate), PBA; poly(hexamethylene adipate), PHMA; and three polycaprolactones, PCL, of different molecular weights ($M_n$ ~10, 40, and 80K). The chemical stability of retinol in these nanoparticles, monitored in an aqueous solution at $25^{\circ}C$ and $40^{\circ}C$ for 4 weeks, was high in the following order of the nanoparticles prepared with PHMA > PCL 40K > PCL 10K > PCL 80K > PBA~PEA at $25^{\circ}C$ and PCL 10K > PCL 40K > PHMA > PCL 80K > PEA > PBA at $40^{\circ}C$. More importantly, this study has also found that the thermal stability of the retinol in the nanoparticles was closely connected with the melting temperatures of polyesters and polyester nanoparticles. The results were further discussed with possible factors - such as sample preparation condition (or history) and miscibility between the polyesters and retinol - affecting $T_m$ of the polyesters and the nanoparticles.