Thermally induced phase transition of poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) investigated by two-dimensional infrared correlation spectroscopy
Thermally induced phase transition of poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) investigated by two-dimensional infrared correlation spectroscopy
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DOI：
10.1016/j.vibspec.2003.11.016
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发表时间：
2004-12-06
影响因子：
2.5
通讯作者：
Ozaki, Y
中科院分区：
文献类型：
--
作者：
Padermshoke, A;Sato, H;Ozaki, Y
新开发的可生物降解聚合物的热诱导结晶/非晶相变过程。聚(3-羟基丁酸酯-co-3-羟基己酸酯) (P(HB-co-HHx)) (HHx = 12 mol%)，通过使用广义二维红外 (2D IR) 相关光谱进行研究。为了探索共聚物的相变行为，对C-H拉伸(3100-2800 cm(-1))、C=O拉伸(1780-1680 cm(-1))和C-O-C拉伸(1330-1200 cm-1)三个光谱区域进行了分析。 C=O伸缩带区域中温度引起的红外光谱变化产生的异步二维光谱清楚地揭示了1731和1723 cm(-1)处两个晶体手的共存。 1723 cm-1 处的主谱带可能由共聚物的高度有序结晶组分产生，而 1731 cm(-1) 处的较弱谱带可能是由于具有不太有序结构的次要结晶组分。 1723 cm(-1) 处的主要结晶带与1740 cm(-1) 处的非晶带共享异步交叉峰。这一观察结果表明晶体结构的熔化并不同时导致完全非晶结构的形成。 P(HB-co-HHx) (12 mol% HHx) 的相变过程通过中间态发生。值得注意的是，由于 P(HB-co-HHx) (12 mol%，Mix) 的结晶成分导致的 C=O、C-O-C 和 C-H 伸缩带的振动频率与 PHB 的振动频率几乎相同。这些观察结果表明 P(HB-co-HHx) (12 mol%.HHx) 的螺旋结构与 PHB 的螺旋结构非常相似。 HHx共聚单体的加入局部地破坏了PHB高度有序的螺旋结构，从而降低了共聚物的结晶度。研究还发现，P(HB-co-HHx) (12 mol% HHx) 的螺旋结构在比 PHB 低得多的温度下逐渐变形。 (C) 2004 Elsevier B.V. 保留所有权利。
The thermally induced crystalline/amorphous phase transition process of a newly developed biodegradable polymer. poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P(HB-co-HHx)) (HHx = 12 mol%), was investigated by using generalized two-dimensional infrared (2D IR) correlation spectroscopy. Three spectral regions, the C-H stretching (3100-2800 cm(-1)), C=O stretching(1780-1680 cm(-1)), and C-O-C stretching (1330-1200 cm-1) band regions were analyzed in order to explore the phase transition behavior of the, copolymer. The asynchronous 2D spectrum generated from the temperature-induced variations in IR spectra in the C=O stretching band region clearly revealed the coexistence of two crystalline hands at 1731 and 1723 cm(-1). The dominant band at 1723 cm-1 may arise from the highly ordered crystalline component of the copolymer, and the weaker band at 1731 cm(-1) is possibly due to the minor crystalline component with a less ordered structure. The major crystalline band at 1723 cm(-1) shares asynchronous cross peaks with the amorphous band at 1740 cm(-1). This observation suggests that the melting of the crystalline structure does not simultaneously result in the formation of the completely amorphous structure. The phase transition process of P(HB-co-HHx) (12 mol% HHx) takes place through an intermediate state. It is noted that the vibrational frequencies of the C=O, C-O-C, and C-H stretching bands due to the crystalline components of P(HB-co-HHx) (12 mol%, Mix) are almost identical to those of PHB. These observations indicate that the helical structure of P(HB-co-HHx) (12 mol%. HHx) is very similar to that of PHB. The inclusion of the HHx comonomer locally disrupts the highly ordered and helical structure of PHB from place to place, thereby reducing the crystallinity of the copolymer. It was also found that the helical structure of P(HB-co-HHx) (12 mol% HHx) is deformed gradually from much lower temperature than that of PHB. (C) 2004 Elsevier B.V. All rights reserved.