• Macromolecular Research
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• 제11권1호
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• pp.62-68
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• 2003

Thermotropic liquid crystalline polymer (TLCP)/poly(ethylene 2,6-naphthalate) (PEN)/poly(ethylene terephthalate) (PET) ternary blends were prepared by melt blending, and were melt-spun to fibers at various spinning speeds in an effort to improve fiber performance and processability. Structure and property relationship of TLCP/PEN/PET ternary blend fibers and effects of annealing on those were investigated. The mechanical properties of ternary blend fibers could be significantly improved by annealing, which were attributed to the development of more ordered crystallites and the formation of more perfect crystalline structures. TLCP/PEN/PET ternary blend fibers that annealed at 18$0^{\circ}C$ for 2 h, exhibited the highest values of tensile strength and modulus. The double melting behaviors observed in the annealed ternary blend fibers depended on annealing temperature and time, which might be caused by different lamellae thickness distribution as a result of the melting-reorganization process during the DSC scans.

• Fibers and Polymers
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• 제7권1호
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• pp.1-7
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• 2006

Interaction of a representative antibiotic, doxycycline(Doxy), with commercial poly(acrylonitrile) (PAN) and cationic-dyeable poly(ethylene terephthalate)(PET) fiber was studied in development of infection resistant biomedical materials. Regular PET was also employed for a comparison purpose. Their interactions were investigated at different treatment temperatures, times, and pHs. Fibers were also hydrolyzed by 1% NaOH for 1 or 2 hours at $85^{\circ}C\;and\;100{\circ}C$ to study effect of hydrolysis on antibiotic sorption. Infection-resistant characteristics of the substrates were evaluated by zone of inhibition (ZOI) test. Results revealed that a significant chemical change occurred in PAN and cationic-dyeable PET due to hydrolysis. Additional functional groups obtained by hydrolysis not only enhanced sorption of the antibiotics but also provided greater ZOI values, indicating substantial improvement in sustained infection resistance properties.

• 한국염색가공학회지
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• 제9권2호
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• pp.17-24
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• 1997

PET/PHE blends were prepared by the mixing of poly(ethylene terephthalate) and poly(hydroxyether of bisphenol A) at melt state above PET melting temperature and modified PET fibers having less than 5 wt% of PHE were also prepared by the melt spinning of the PET/PHE blends. The PET/PHE blends were able to prepare by means of physical mixing concept, except the chemical interaction between hydroxyl groups of PHE and ester groups of PET. It has been revealed that the modified PET fibers have some hydrophilic properties such as low contact angle and easy-dyeable characters.

• Fibers and Polymers
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• 제7권3호
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• pp.270-275
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• 2006

The dyeability of poly(lactic acid) [PLA] with a range of commercial disperse dye was examined and compared to that of poly(ethylene terephthalate) [PET] in addition to the colour and fastness of the resultant dyeings. A screening exercise in which twenty dyes of differing energy types and chemical classes were applied to PLA revealed a substantial variation between the dyes in terms of dye uptake (12-88 % at 4 % o.w.f.). Nine dyes exhausted above 70 % and were selected for further study, which involved comparison of shade and fastness of PLA dyeings with those of the corresponding PET dyeings. Differences in shade depended on hue while wet fastness of each of the PLA dyeings was either the same or 0.5-1.0 point lower than its PET counterpart. In all but one case, dye photostability in PLA was found to be very similar to that in PET. Dye build-up profiles on PLA were also investigated and from these results mixtures of compatible dyes identified.

• Environmental Engineering Research
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• 제11권5호
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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.

• Korean Chemical Engineering Research
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• 제51권1호
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• pp.144-150
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• 2013

본 연구에서는 촉매로 zinc acetate를 사용하였고 dimethyl terephthalate(DMT)와 ethylene glycol(EG)의 에스테르 교환을 통하여 polyethylene terephthalate(PET)의 단량체인 bishydroxyethyl terephthalate(BHET)를 생성하는 반응에 대하여 알아보았다. 기존의 kinetics 연구는 에스테르 교환 반응에서 생성되는 메탄올이 반응계에서 제거되는 반회분식공정을 바탕으로 하여 이때 제거된 메탄올 양을 측정하여 역반응이 무시된 반응 kinetics 모델을 구성하였다. 본 연구에서는 회분식 반응기를 통하여 DMT와 메탄올의 양을 정량하여, 역반응을 고려한 보다 정확한 kinetics 모델을 제안하였고, 제안된 모델의 예측값들이 실험값들과 잘 일치하는 것을 보였다. 또한 모델과 실험값을 분석하여 여러 공정 변수들이 에스테르 교환 반응에 미치는 영향을 조사하였다.

• 한국의류산업학회지
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• 제15권2호
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• pp.302-308
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• 2013

This study is a preliminary investigation of the influence of surface characteristics of substrates on detergency of particulate soil. The surface of PET film was modified with NaOH and NaOH+ethylene diamine on different times. The surface morphology of the film was scanned by AFM and surface energies were calculated from measured contact angles between several solutions and film based on the geometric mean and a Lewis acid base method. The surface morphology of PET film treated with NaOH and NaOH+ethylene diamine became more etched, and the surface area, surface roughness and the coefficient of friction of film increased with treatment of NaOH and NaOH+ethylene diamine. The contact angle of film treated with NaOH and NaOH+ethylene diamine decreased in water and surfactant solution; in addition, the surface energy increased was largely attributed to the increased portion on the polar surface energy of film. However, the effect of the diamine addition to the NaOH treatment solution on surface characteristics of PET film was insignificant.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1999년도 가을 한국섬유공학회 학술발표회 논문집(Proceedings of the Korean Textile Conference)
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• pp.123-126
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• 1999

• 한국유변학회:학술대회논문집
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• 한국유변학회 2002년도 춘계 학술발표회 논문집
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• pp.159-162
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• 2002

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1991년도 제2차 학술발표초록집
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• pp.33-34
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• 1991