基于近红外光谱的棉纤维素纤维降解机理研究

近红外光谱技术已经有效应用于表征原材料和经过后整理的纺织产品．基于相对简单的近红外光易识别的化学基团（如：C—H，O—H和N—H），该技术已发展成为聚合物产品最重要的表征方法之一．通过近红外光谱分析定量化表征历史纺织品“Curtain Dress”中的棉纤维素纤维降解程度，研究同一棉纺织产品中引起诸如颜色等不同外观变化的纤维结构形态和大分子结构变化机理．利用Brimrose Luminar 5030近红外分析仪测试获得了“Curtain Dress”包括上身和裙子的8处不同程度褪色区域的近红外光谱，根据近红外光谱吸收峰识别了棉纤维素纤维的典型官能团C—H、C—O和0一H等．并通过主元分析法（PCA,Principle component analysis）分析了不同褪色区域的功能基团振动变化．研究发现第一和第二主成分的因子综合得分F很好地解释了分子中各组成键原子高达99．09％的振动变化程度，有效地反映了在褪色过程中纤维结构与形态变化机理．

NIR spectral analysis for characterizing degradation of cotton cellulosic fibers

Near Infrared （NIR） spectroscopy has been found to be a useful technique to charac- terize raw material and finished textile products. It has developed into one of the most important characterizations of a polymeric product based on its comparatively simple NIR-favorable chemical species or groups （i. e. , C--H, O--H, and N--H）. This paper is aimed to characterize quantitatively degradation of cotton cellulosic fibers in a historical textile--＇ Curtain Dress＇ through near infrared spectroscopy, and to study the morphological and molecular factors causing appearance change such as discolorations in the same cotton textiles. In this study, we did on-site testing on the ＇Curtain Dress＇ with the Brimrose Luminar 5030 NIR-analyzer and ana- lyzed the NIR spectroscopy results at eight locations with different degrees of discoloration on the dress. The study identified the bands according to NIR spectral absorbencies of the typical functional groups of cotton cellulosic fibers such as C--H stretch, C--O stretch and O--H, and observed that in different areas of discoloration they changed considerably via principal component analysis. The combination factor scores （F） of the 1^st and 2^nd principal components, which accounted for 99.09% variance of vibrations within various groups of bonded atoms in a molecule measured through NIR, reflected effectively morphological changes in the fiber＇s molecular structure and degrees of discolorations.