Jiang Hongjin, Wu Peiyi, Yang Yuliang
Department of Macromolecular Science, The Key Laboratory of Molecular Engineering of Polymers, Ministry of Education, Fudan University, Shanghai, 200433 China.
Biomacromolecules. 2003 Sep-Oct;4(5):1343-7. doi: 10.1021/bm0341069.
A recently developed technique, i.e., two-dimensional infrared (2D IR) correlation spectroscopy, is used to study the thermal behavior of poly(ethylene-co-vinyl alcohol)-graft-poly(epsilon-caprolactone), a new synthesized highly grafted copolymer. The use of the 2D IR approach to analyze temperature-dependent spectra collected in situ during the temperature elevation process effectively enhanced the spectral resolution and revealed details on the hydrogen bonding and conformational change which are not easily detected in the traditional one-dimensional spectra. The sequence of the spectral changes of different OH and CH(2) fundamental vibrations during heating the polymer was inferred from the signs of the asynchronous peaks. Evidence that the conformational changes of the methylene groups precede the loosening of hydrogen bonds is provided.
一种最近开发的技术，即二维红外（2D IR）相关光谱法，被用于研究聚（乙烯 - 共 - 乙烯醇） - 接枝 - 聚（ε - 己内酯）的热行为，这是一种新合成的高度接枝共聚物。使用二维红外方法分析在升温过程中原位收集的温度相关光谱，有效地提高了光谱分辨率，并揭示了传统一维光谱中不易检测到的氢键和构象变化的细节。从异步峰的符号推断出聚合物加热过程中不同OH和CH(2)基本振动的光谱变化顺序。提供了亚甲基构象变化先于氢键松弛的证据。
