微晶纤维素的FTIR研究

Study on the FTIR of microcrystalline celluloses

研究了两种不同晶型的微晶纤维素的傅立叶变换红外光谱及广角X-射线衍射谱。发现了纤维素Ⅰ型和纤维Ⅱ型的微晶纤维素的红外光谱在OH伸缩振动区均分裂为两个峰，并且它们的红外光谱的区别在于分子链堆砌的不同。

The wide angle X-ray diffraction (WAXD) and the fourier transform infrared spectrums of two different crystal types of microcrytalline celluloses were studied. The WAXD indicated that the microcrystalline celluloses studied belonged to the members of the cellulose Ⅰ and cellulose Ⅱ families, respectively, and their crystallinities was high. The FTIR showed that both cellulose Ⅰ and cellu1ose Ⅱ have two absorbed peaks in the OH stretching region. These two peaks were caused by the functions of intramolecular hydrogen bond and intermolecular hydrogen bond. It was seen that the bands in cellulose I at 1430cm-1 and 1112cm-1 were strong, while the corresponding bands in cellulose II at 1421 cm-1 and 1112cm-1 were weak. In addition, there was a definite differenbe at about 900cm-1 between cellulose Ⅰ and cellulose Ⅱ. The difference of their FTIR spectrums was attributed to the difference of their lnolecular chain packages.