Melt crystallization and crystal transition of poly(butylene adipate) revealed by infrared spectroscopy.
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.
Yan
Chao
C
Department of Physics, School of Science and Technology, Kwansei-Gakuin University, Gakuen, Sanda 669-1337, Japan.
Zhang
Ying
Y
Hu
Yun
Y
Ozaki
Yukihiro
Y
Shen
Deyan
D
Gan
Zhihua
Z
Yan
Shouke
S
Takahashi
Isao
I
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
D001672:Biocompatible Materials; D002072:Butylene Glycols; D011108:Polymers; C009204:butylene glycol adipic acid polyester