作者：Li Xiangyang; Hong Zhenfei; Sun Jie; Geng Yong; Huang Youju; An Haining; Ma Zhe; Zhao Baijin;Shao Chunguang; Fang Yapeng; Yang Chuanlu; Li Liangbin*
關鍵字：Phase Behavior,Biodegradable Poly(hexamethylene succinate-co-hexamethylene adipate) Copolymers,FTIR
論文來源：期刊
具體來源：J. Phys. Chem. B 2009, 113, 2695–2704
發表時間：2009年
Whether a phase separation or a cocrystallization occurs in poly(hexamethylene succinate-co-hexamethylene
adipate) (P(HS-co-HA)) copolymers was studied with a combination of wide-angle X-ray diffraction (WAXD)
and Fourier transform infrared (FTIR) spectroscopy. With HA as the majority, the presence of HS comonomers
leads to weakening and broadening of (10l) peaks in the X-ray fiber diffraction patterns, while a crystal
structure similar to PHS is formed in the copolymer with HS as the majority. The X-ray diffraction patterns
imply possible cocrystallization between HS and HA comonomers, but cannot lead to an unambiguous
conclusion, which was clarified with the compensative tool of FTIR. Following the characteristic absorption
bands of crystals, cocrystallization of HS and HA comonomers was observed in copolymers with HA
comonomer as the majority during which HA initiated the nucleation at high temperatures. With HA as
minority, cocrystallization of HS and HA can still be achieved with a fast quenching to below 0 °C, while a
phase separation occurs and only HS comonomer crystallizes at high temperatures. This demonstrates that
P(HS-co-HA) has an asymmetric phase diagram. Because of the sensitivity to local conformations, FTIR
spectroscopic method is demonstrated to be a powerful tool on study phase behaviors of polymers with similar
crystal structure.