小麦秸秆纵向剖片的漂白与染色

Bleaching and Dyeing of Longitudinal Slice of Wheat Straw

沿小麦秸秆纵向剖开制备麦秸剖片,测试了剖片的成分组成;麦秸剖片经碱预处理后,再经双氧水漂白,优化了漂白工艺参数,采用活性染料三原色对漂白麦秸剖片进行染色,测试了其染色性能.结果表明:秸秆剖片主体成分的质量分数从大到小依次为纤维素、木质素、半纤维素,三者质量分数之和超过90%;麦秸剖片原样的润湿与亲水性能差,经碱预处理后,剖片的润湿与亲水性能有所提升;优化后的双氧水漂白工艺参数,即30%双氧水质量浓度为60g/L,硅酸钠质量浓度为0.5g/L,漂白温度为98℃,漂白时间为90min,浴比为200∶1;相比麦秸剖片原样,染料三原色对漂白麦秸剖片染色的上染率显著提升,染色后剖片的饱和度、颜色深度增加,其耐洗和干湿摩擦牢度均高于3级;测试表明经碱预处理与漂白工艺后,秸秆表面蜡质层去除,原纤形貌清晰,麦秸表面沟槽明显,比表面积增加,有助于染液的渗透与扩散.

Slice of wheat straw which was prepared from cutting along the longitudinaldirection of wheat straw, and its component was measured firstly. Then, the slice was treated by alkali pretreatment followed by hydrogen peroxide bleaching, and the bleaching process was optimized. Meanwhile, the dyeing performance of the slice dyed by reactive trichromatic was analyzed. Results show that the main components are cellulose, lignin and hemicellulose from large to small in order, and the sum of three components is more than 90% of mass fraction. The wetting and hydrophilicity of the original wheat straw slice are poor, but both the properties of slice are improved after alkali pretreatment. The optimized bleaching of wheat straw slice is containing 30% hydrogen peroxide and sodium silicate with the mass concentration of 60 g/L and 0.5 g/L respectively, and the bleaching is kept at 98 ℃ for 90 min with the liquor-to-goods ratio of 200： 1. Compared with original wheat straw slices, when the bleached slice is dyed by trichromatic reactive dyes, the dyeing rate is significantly improved, the saturation and color depth increase, and the color fastness including washing and dry and wet rubbing fastness are both higher than 3 grade. Results also show that the wax layer coated on the surface of wheat straw is removed after the alkali treatment and bleaching process, the fibril morphology is clear, the surface groove of the wheat straw is obvious and the specific surface area is increased, which will be help to dye penetration and diffusion.