利用傅里叶变换光谱技术分析拉伸羊毛的二级结构

Secondary structure analysis of stretched wool using Fourier transform spectroscopy

利用傅里叶变换红外光谱、傅里叶变换偏振红外光谱及傅里叶变换拉曼光谱技术分别对不同拉伸率(0、30%、50%)下的羊毛二硫键、分子链段取向结构及大分子构象的变化进行了分析.结果表明:羊毛纤维拉伸率越大,二硫键断裂越多;随着拉伸率的增大,部分α-螺旋链转化为β折叠链形式,二向色性比值减小,但减小的幅度不大;在拉伸羊毛的构象分析中可知,酰胺I带中,随着拉伸率的提高,α-螺旋含量减少,β折叠构象和无规卷曲构象的含量增加;酰胺III带中,拉伸初期主要改变的是纤维中微原纤的结构,微原纤从α-螺旋结构转变为β折叠结构,当拉伸率提高后,纤维结构的变化主要是内部基质及细胞间质的变化.

The S-S bond, macromolecule structure and macromolecule conformation transform of stretched wool fibers with stretching rated 0,30% and 50% are investigated by FTIR, FT-Polarized IR and FF-Raman Spectroscopy. It is found that S-S bond breaks as the draw ration increases. Some α-helix transform to β-sheet, dichroic ratio slightly decreases. Meanwhile, in the amide I, α-helix decreases while/S-sheet and random coil increase with the increase of stretching rate of wool fiber. In the amide III, it could be included that the structural of microfibril is mainly changed in the initial stages of stretch and the structure transform from α- helix to B-sheet; structural slippage of matrix and cell membrane complex of wool fiber occurs when the stretching rate is increased.