• Title/Summary/Keyword: terephthalate

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Effect of Transesterification on the Physical Properties of Poly(butylene terephthalate)/Poly(ethylene terephthalate) Blends (상호에스테르 교환반응이 폴리(부틸렌 테레프탈레이트)/폴리(에틸렌 테레프탈레이트) 블렌드 물성에 미치는 영향)

  • Kim Hoy-Kap;Kim Jun-Kung;Lim Soon-Ho;Lee Kun-Wong;Park Min;Kang Ho-Jong
    • 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.

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Synthesis and Non-Isothermal Crystallization Behavior of Poly (ethylene-co-1,4-butylene terephthalate)s

  • Jinshu Yu;Deri Zhou;Weimin Chai;Lee, Byeongdu;Le, Seung-Woo;Jinhwan Yoon;Moonhor Ree
    • Macromolecular Research
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    • v.11 no.1
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    • pp.25-35
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    • 2003

  • A series of random poly(ethylene-co-1,4-butylene terephthalate)s (PEBTs), as well as poly(ethylene terephthalate) (PET) and poly(1,4-butylene terephthalate) (PBT), were synthesized by the bulk polycondensation. Their composition, molecular weight, and thermal properties were determined. All the copolymers are crystallizable, regardless of the compositions, which may originate from both even-atomic-numbered ethylene terephthalate and butylenes terephthalate units that undergo inherently crystallization. Non-isothermal crystallization exotherms were measured over the cooling rate of 2.5-20.0 K/min by calorimetry and then analyzed reasonably by the modified Avrami method rather than the Ozawa method. The results suggest that the primary crystallizations in the copolymers and the homopolymers follow a heterogeneous nucleation and spherulitic growth mechanism. However, when the cooling rate increases and the content of comonomer unit (ethylene glycol or 1,4-butylene glycol) increases, the crystallization behavior still becomes deviated slightly from the prediction of the modified Avrami analysis, which is due to the involvement of secondary crystallization and the formation of relatively low crystallinity. Overall, the crystallization rate is accelerated by increasing cooling rate but still depended on the composition. In addition, the activation energy in the non-isothermal crystallization was estimated.

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Synthesis and Properties of PET-PCT Copolyester I - Thermal Property and Degradation Behavior - (PET-PCT 공중합체의 합성과 물성 I - 열적성질과 분해거동 -)

  • 이원옥;김해영;백두현
    • Proceedings of the Korean Fiber Society Conference
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    • 2001.10a
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    • pp.351-354
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    • 2001

  • Poly(ethylene terephthalate) (PET)는 물리적, 기계적 성질이 우수한 엔지니어링 플라스틱의 하나로 섬유, 필름, 및 여러 가지 용도로 다양하게 사용되고 있다. PET는 DMT(dimethyl terephthalate) 또는 TPA(terephthalic acid)와 EG(ethylene glycol)를 축합 중합하여 제조한다. (중략)

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