title: Melt crystallization and crystal transition of poly(butylene adipate) revealed by infrared spectroscopy.
abstract: The structure evolution of poly(butylene adipate) (PBA) during isothermal melt crystallization and phase transition processes is investigated by Fourier transform infrared spectroscopy (FTIR). Detailed IR spectra analysis and band assignment are performed to disclose the bands sensitive to the alpha-form crystalline order of PBA. It is revealed from the in situ IR study that the functionalities within PBA chains alter simultaneously during the melt crystallization process. From the analysis of the spectral changes, it is found that band shifts take place during the phase transition process of PBA from its metastable beta-form crystal to the stable alpha-form. Notable band shifts in the 1300-1100 cm(-1) region indicate that the twist of polymer chains in the alpha-form is located in the C-O-C and C-O linkages. Moreover, the results elucidated that the different segments of molecular chains tune up their conformations synchronously during the beta to alpha crystal transition process of PBA. It is suggested that the betaalpha phase transition process proceeds randomly throughout the solid at a constant rate.
authors.affiliation: Department of Physics, School of Science and Technology, Kwansei-Gakuin University, Gakuen, Sanda 669-1337, Japan.
authors.forename: Chao
authors.initials: C
authors.lastname: Yan
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yun
authors.initials: Y
authors.lastname: Hu
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Ozaki
authors.forename: Deyan
authors.initials: D
authors.lastname: Shen
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Gan
authors.forename: Shouke
authors.initials: S
authors.lastname: Yan
authors.forename: Isao
authors.initials: I
authors.lastname: Takahashi
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D002072:Butylene Glycols / Q000737:chemistry*; D003460:Crystallization; D044367:Phase Transition; D011108:Polymers / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013997:Time Factors
chemical_list: D001672:Biocompatible Materials; D002072:Butylene Glycols; D011108:Polymers; C009204:butylene glycol adipic acid polyester