• Title/Summary/Keyword: terephthalate

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Recycling of Poly(ethylene terephthalate) via Methanolysis without Catalyst (무촉매 메탄올 분해에 의한 Poly(ethylene terephthalate)의 재활용에 관한 연구)

  • Lee, Yoon-Bae;shin, Jae-Sick
    • Clean Technology
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    • v.8 no.1
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    • pp.39-44
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    • 2002
  • In order to recycle poly(ethylene terephthalate), methanolysis has been investigated at elevated temperature and under high pressure without catalyst to afford dimethyl terephthalate and ethylene glycol. The reaction was carried out under 62 atm, $310^{\circ}C$ for 50min to obtain 98% dimethyl terephthalate. The method has been suggested as a simple and economical one to recycle the poly(ethylene terephthalate).

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Study on the Hydrophilicity of Modified Polyester (개질시킨 폴리에스테르 중합체의 친수성 연구)

  • Jung, Byung-Ok
    • Applied Chemistry for Engineering
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    • v.9 no.6
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    • pp.930-934
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    • 1998
  • The modified poly(ethylene terephthalate) (PET) was synthesized by copolymerizing dimethyl terephthalate with ethylene glycol, polyethyleneglycol, and dodecylbenzene sulfonate as a surfactant. After characterization of viscosity, color, and contant angle, hydrophilic characteristics of the modified PET depending on additives was discussed.

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Physical Properties of Poly(ethylene terephthalate)-Poly(1, 4-phenylene terephthalate) Copolyester (Poly (ethylene terephthalate)-Poly (1, 4-phenylene terephthalate) Copolyester의 물성)

  • Ahn, Tae Oan;Nam, Byeong Uk;Park, Jong-Yoon
    • Applied Chemistry for Engineering
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    • v.2 no.3
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    • pp.246-252
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    • 1991
  • Copolyesters (PEHT) of poly (ethylene terephthalate) (PET) and poly (1,4-phenylene terephthalate) (PHT) were synthesized by the solution polymerization with the PHT unit contents of less than 30 mol %, and their physical properties were studied. As the content of PHT unit in PEHT was increased, glass transition temperature, crystallization rate, thermal stability increased, whereas melting temperature decreased. When the PHT unit contents were 16.5 and 24.9 mol%, nematic mesophase was observed. Wide angle X-ray diffraction pattern showed the peaks originated from both PET unit and PHT unit.

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Interchange Reaction Kinetics and Sequence Distribution of Liquid Crystalline Poly(ethylene terephthalate-co-2(3)-chloro-1,4-phenylene terephthalate)

  • Rhee, Do-Mook;Ha, Wan-Shik;Youk, Ji-Ho;Yoo, Dong-Il
    • Fibers and Polymers
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    • v.2 no.2
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    • pp.86-91
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    • 2001
  • Liquid crystalline (LC) poly(ethylene terephthalate-co-2(3)-chloro-1,4-phenylene terephthalate) [copoly(ET/CPT)] was prepared using poly(ethylene terephthalate) (PET) as a flexible spacer, terephthalic acid (TPA), and chlorohydroquinone diacetate (CHQDA). All reactions involved in the copolymerization were investigated using some model compounds: TAP was used for acidolysis, diphenylethyl terephthalate (DPET) for interchange reaction between PET chains, and 야-o-chlorophenyl terephthalate (DOCT) and di-m-chlorophenyl terephthalate (DMCT) for interchange reaction between PET and rigid rodlike segments. Activation energies obtained for the acidolysis of PET with TPA and for interchange reaction of PET with DPET, DOCT, and DMCT were 19.8 kcal/mol, 26.5 kcal/mole, and 45.9 kcal/mole, respectively. This result supports that the copolymerization proceeds through the acidolysis of PET with TPA first and subsequent polycondensation between carboxyl end group and CHQDA or acetyl end group, which is formed from the reaction of CHQDA and TPA. Also, it was found that ester-interchange reaction can be influenced by the steric hindrance. Copoly(ET/CPT)s obtained has ethylene acetate end groups formed from acetic acid hydroxy ethylene end groups and showed almost the random sequence distribution for all compositions.

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Synthesis of Terephthalate Intercalated Zn-Al Layered Double Hydroxides Using AZO Thin Film (AZO박막을 이용한 Terephthalate가 삽입된 Zn-Al 층상 이중 수산화물의 합성)

  • Park, Ki-Tae;Yoon, Soon-Gil
    • Korean Journal of Materials Research
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    • v.27 no.3
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    • pp.161-165
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    • 2017
  • In this paper, synthesis of terephthalate intercalated Zn-Al: Layered double hydroxides (LDHs) was studied. We designed freestanding Zn-Al: carbonate LDH nanosheets for a facile exchange technique. The as-prepared Zn-Al carbonate LDHs were converted to terephthalate intercalated Zn-Al:LDHs by ion exchange method. Initially, Al-doped ZnO (AZO) thin films were deposited on p-Si (001) by facing target sputtering. For synthesis of free standing carbonate Zn-Al:LDH, we dipped the AZO thin film in naturally carbonated water for 3 hours. Further, Zn-Al: carbonate LDH nanosheets were immersed in terepthalic acid (TA) solution. The ion exchange phenomena in the terephthalate assisted Zn-Al:LDH were confirmed using FT-IR analysis. The crystal structure of terephthalate intercalated Zn-Al:LDH was investigated by XRD pattern analysis with different mole concentrations of TA solution and reaction times. The optimal conditions for intercalation of terephthalate from carbonated Zn-Al LDH were established using 0.3 M aqueous solution of TA for 24 hours.

Transesterification Kinetics of Bis(2-Hydroxyethyl) Terephthalate with 1,4-Butandiol (Bis(2-Hydroxyethyl) Terephthalate와 1,4-Butanediol의 에스테르 교환 반응)

  • Jeon, Hyeongcheol;Han, Myungwan
    • Korean Chemical Engineering Research
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    • v.56 no.1
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    • pp.103-111
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    • 2018
  • Transesterification of BHET (Bis (2-Hydroxyethyl) Terephthalate), monomer of PET (Poly Ethylene Terephthalate) to BHBT (Bis (4-Hydroxybutyl Terephthate), monomer of PBT (Poly Butylene Terephthalate), using 1,4-BD (1,4-butanediol) were investigated. Zinc acetate was used as a catalyst for the reaction. Amounts of BHET, EG, and THF (Tetrahydrofuran) in a batch reactor were measured for determining the reaction kinetics. Mathematical models of the batch reactor for the transesterification reaction were developed and used to characterize the reaction kinetics and the composition distribution of the reaction products. Model predictions for the transesterification were in good agreement with experimental results.

Sequence Distribution and Thermal Properties of Poly(butylene succinate-co-butylene terephthalate) Copolyesters (Poly(butylene succinate-co-butylene terephthalate) 공중합물의 미세구조와 열적 성질)

  • Park, Sang Soon;Jeong, Jae Ho;Kim, Tae Jeong;Kim, Dae Jin;Im, Seung Soon
    • Journal of the Korean Chemical Society
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    • v.40 no.1
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    • pp.87-95
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    • 1996
  • The binary random copolyesters of poly(butylene succinate-co-butylene terephthalate) (PBS/PBT) were synthesized and their sequence distributions were investigated over the entire range for PBS/PBT copolyester compositions by 1H NMR spectroscopy. The melting point (Tm) of these copolyesters were depressed gradually with the increase of dimethyl terephthalate (DMT) mol% in composition and appeared an eutetic behaviour which appears a minimum at ST3 (DMT 65.8 mol%). The melting behaviour of PBS/PBT copolyester was not directly depended on molar fraction (Xa) but on only the sequence propagation probability (P) which occurs in triad fraction. It also can be seen that when the succinate units (or terephthalate units) were abundant enough, PBS/PBT Copolymers formed only PBS (or PBT) crystal with complete rejection of the terephthalate units (or succinate units).

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Sequence Distribution and Thermal Property of Poly(butylene glutarate-co-adipate-co-succinate-co-terephthalate) Copolyesters (Poly(butylene glutarate-co-adipate-co-succinate-co-terephthalate) 공중합체의 서열분포 및 열적성질)

  • Park, Sang Soon;Cho, Yoon;Kang, Hye Jung
    • Journal of the Korean Chemical Society
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    • v.43 no.6
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    • pp.682-690
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    • 1999
  • The quaternary random copolyesters of poly (butylene glutarate-co-adipate-co-succinate-co-terephthalate)(PBGAST) were synthesized and charaterized by $^1H-NMR$ spectrometry, DSC method, and X-ray diffractometry. Thus the melting point trends and crystallization behaviors of PBGAST copolyesters were obviously depended on terephthalate content in copolymers as well as reaction condition.

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Sequence Structure and Thermal Property of Poly(butylene terephthalate) (PBT)/p-Acetoxybenzoic Acid (ABA) Copolymers Obtained Through Melt Trans-esterification Reaction (용융 에스테르 교환반응에 의해 제조된 폴리부틸렌테레프탈레이트/파라아세톡시벤조산 공중합체의 서열구조와 열적 성질)

  • 김도경;박수영;박종래
    • Polymer(Korea)
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    • v.24 no.1
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    • pp.58-64
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    • 2000
  • Poly(butylene terephthalate-co-oxybenzoate) (PBOT ) was synthesized by melt trans-esterification of poly(butylene terephthalate)(PBT) and p-acetoxybensoic acid (ABA) at 250, 260, and 27$0^{\circ}C$ with the compositions of PBT/ABA of 4/6, 5/5, 6/4. The sequence analysis of PBOT with a $^1$H FT-NMR indicated that the number of consecutive oxybenzoate units ranges from 1.2 to 1.5, which is larger than that of the corresponding poly(ethylene terephthalate)(PET)/ABA (PEOT) obtained at the same reaction conditions as the PBOT. The difference in the block length influenced the thermal degradation behavior: Polyoxybezoate (POB), PBT and PEOT showed one-step degradation whereas PBOT exhibited two-step degradation. The results suggested that PBOT consisted of three phases of PBT-rich phase, random phase of PBT and ABA, and ABA-rich phase.

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