化学合成半乳糖基纤维素

Chemical synthesis of galactose-branched cellulose

本文研究了一种在酸性条件下合成半乳糖基纤维素的化学方法,探讨了反应时间、纤维素与半乳糖的投料比对共聚物中半乳糖摩尔取代度(MS)的影响。在酸性条件下,纤维素与半乳糖共聚时,少量的半乳糖接枝到纤维素上形成水不溶物,即半乳糖基纤维素;而其余的半乳糖与纤维素降解的少量葡聚糖片段共聚形成水溶物。反应时间从50 min延长到120 min,水不溶物的半乳糖MS基本保持0.12不变;而反应时间为150 min时,水不溶物的半乳糖MS降低为0.073;水溶物主要是由半乳糖组成,葡萄糖含量少。增加半乳糖用量,水不溶物的半乳糖MS增加最后保持0.094不变;随着反应物中半乳糖含量的增加,水溶物的半乳糖MS也是先增加,后保持基本保持15不变。

A chemical method is presented for modification of cellulose with galactose under acidic conditions.The effects of time and feedstock ratios of cellulose to galactose on the molar substitution（MS）of galactose in copolymer were investigated.We propose that the copolymerization undergoes in a way that a small amount of galactose grafted onto cellulose result in the water-insoluble composition,and the glucose chains cut-off from the cellulose combine with galactose to generate water-soluble composition in copolymer.Time trials from 50 min to 120 min show that the MS of galactose of the water-insoluble composition was unchanging at 0.12;when time was 150 min,the MS of galactose of the water-insoluble composition dropped to 0.073;the water-soluble composition is mainly consisted of galactose.With the increase of galactose,the MS of galactose of the water-insoluble composition increases and was unchanging at 0.094;while the MS of galactose in water-soluble composition increases and was constant at 15.