The conformational changes,crystal structure and melting behavior of poly(ethylene/ trimethylene terephthalate) copolyesters |
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| Authors: | Tien‐Wei Shyr Chia‐Hsing Tung Wen‐Sheng Cheng Shi‐Dong Jiang Shou‐Ke Yan Zhi‐Hua Gan |
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| Affiliation: | 1. Department of Fiber and Composite Materials, Feng Chia University, No. 100, Wenhwa Rd, Seatwen, Taichung 40724, Taiwan;2. State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China;3. Department of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China;4. State Key Laboratory of Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China |
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| Abstract: | The conformational changes, crystal structure and melting behavior of poly(ethylene/trimethylene terephthalate) (ET) copolyesters were investigated using in situ Fourier transform infrared (FTIR) spectroscopy, wide‐angle X‐ray diffraction (WAXD), transmission electron microscopy (TEM) and differential scanning calorimetry (DSC) under isothermal crystallization conditions. The results show that the minimum melting temperature was observed in ET53, in which the relative amount of ethylene glycol (EG) to 1,3‐propanediol (PDO) was 52.68/47.32 and the PDO‐dimethyl terephthalate (DMT)‐PDO segments in the molecular chain dominated the crystal formation. The minimum crystallinity of ET copolyesters was found in ET66, in which the relative amount of EG/PDO was 65.91/34.09 and the EG‐DMT‐EG segments in the molecular chain dominated the crystal formation. A rapid and continuous conformational transition in ET copolyesters was observed using in situ FTIR in the first 10 min under isothermal crystallization conditions. The continuously adjusting conformation in the molecules reflects the crystallization of ET copolyesters. Based on the DSC and the X‐ray analyses of the crystallization behavior in the ET copolyesters, crystalline conformation transitions of molecules in ET copolyesters take place rapidly and early. Copyright © 2012 Society of Chemical Industry |
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| Keywords: | conformation transition crystallinity poly(ethylene/trimethylene terephthalate) copolyesters WAXD deconvolution melting temperature |
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