彩棉纤维的形态结构、超微结构和主要化学组成

Study on Morphological Structure, Ultra-microstructure and Composition of Naturally Colored Cotton Fiber

用光学显微镜、透射电镜观察彩棉纤维 ,其形态结构与白棉相似 ,但胞腔大、次生胞壁薄 ,色素主要分布在纤维次生胞壁中。绿棉纤维次生胞壁中有同轴嗜锇层 ,白棉和棕棉则不存在 ;绿棉同轴嗜锇层与蜡质含量、色素有关。彩棉纤维化学全元素分析表明 ,其纤维素含量仅占 85 %～ 90 %;绿棉其余物质成分主要为蜡质 ,含量约是白棉的 6～ 13倍。绿棉蜡质中 ,脂肪烃含量约为 95 %以上 ,主要成分为 C2 2 ～C2 4ω-羟基脂肪酸和二羧酸 ,且含有羟基、羰基、羧基、芳环、酯键、醚键等化合物 ;白棉蜡质的主要成分为 C1 6～C1 8组分。彩棉灰分含量约是白棉的 1.4～ 1.6倍 ,蛋白质含量约是白棉的 1.75～2 .1倍。等离子光谱分析表明 ,彩棉中大多数微量金属含量少于白棉 ,但铜离子和铁离子的含量高于白棉。

The colored cotton fiber is similar to white cotton in morphological structure through the observation by optical microscope and transmission electron microscope. While the former has larger cell and thinner secondary cell wall than the later, most colorant are distributed in the secondary cell wall. The osmiophilic concentric rings, which is contributed to wax and colorant, only exists in the secondary cell wall of green cotton while not of white and brown cotton. Chemical composition analysis shows that the cellulose content is 85～90 %. The others in green cotton are wax, its content is 6～43 times that of white cotton. The ash content of colored cotton is 1. 4～1. 6 times that of white cotton, and the protein content is 1. 75～2. 1 times that of white cotton.