Department of Physical Chemistry, University of Duisburg-Essen, Schuetzenbahn 70, 45117 Essen, Germany.
Appl Spectrosc. 2009 Dec;63(12):1351-5. doi: 10.1366/000370209790109030.
In the present study, the orientation of a poly(3-hydroxybutyrate) (PHB)/poly(epsilon-caprolactone) (PCL) blend was monitored during uniaxial elongation by rheo-optical Fourier transform infrared (FT-IR) spectroscopy and analyzed by generalized two-dimensional correlation spectroscopy (2D-COS). The dichroism of the delta(CH(2)) absorption bands of PHB and PCL was employed to determine the polymer chain orientation in the PHB/PCL blend during the elongation up to 267% strain. From the PHB and PCL specific orientation functions it was derived that the PCL chains orient into the drawing direction while the PHB chains orient predominantly perpendicular to the applied strain. To extract more detailed information about the polymer orientation during uniaxial elongation, 2D-COS analysis was employed for the dichroic difference of the polarization spectra recorded during the drawing process. In the corresponding synchronous and asynchronous 2D correlation plots, absorption bands characteristic of the crystalline and amorphous regions of PHB and PCL were separated. Furthermore, the 2D-COS analysis revealed that during the mechanical treatment the PCL domains orient before the PHB domains.
在本研究中，通过流变光学傅里叶变换红外（FT-IR）光谱监测了聚（3-羟基丁酸酯）（PHB）/聚（ε-己内酯）（PCL）共混物在单轴拉伸过程中的取向，并通过广义二维相关光谱（2D-COS）进行了分析。采用 PHB 和 PCL 的 delta(CH(2))吸收带的二色性来确定 PHB/PCL 共混物在拉伸至 267%应变过程中的聚合物链取向。从 PHB 和 PCL 的特定取向函数中得出，PCL 链沿拉伸方向取向，而 PHB 链主要垂直于施加的应变取向。为了提取在单轴拉伸过程中聚合物取向的更详细信息，对在拉伸过程中记录的偏振光谱的二色性差异进行了 2D-COS 分析。在相应的同步和异步二维相关图中，分离出了 PHB 和 PCL 的结晶和非晶区的特征吸收带。此外，2D-COS 分析表明，在机械处理过程中，PCL 域先于 PHB 域取向。
