摘要:
以纤维素为原料,通过二氧化氮和过碘酸化学氧化方法,在不同的低取代度条件下,有选择性地在纤维素葡萄糖残基的不同碳原子部位导入特定的取代基(羧基和二醛基),探讨不同的取代基对纤维素生物降解性能的影响;并将处理后所得的纤维素试料,通过土壤埋没,利用土壤中的微生物自然降解,然后测定分子量的变化,定量分析纤维素在不同取代基、不同程度化学处理后,其生物降解性能的变化.实验结果表明:(1)在纤维囊葡萄糖残基C6位轻度导入一定量(3%)的羧基,对纤维素的生物降解性能无不利影响,进一步导入羧基(含量15%),则其生物降解性能有明显提高;(2)在葡萄糖残基C2,C3位导入适量(10%左右)的二醛基,有利于纤维素生物降解性能的提高.
Abstract:
Cellulose powder as original material was treated by two different chemical oxidation processing with NO2 and periodic acid, at different low DS (degree of substitution), and special substituent groups could be added into different carbons in cellulosic glucose residue selectively.In this way,the influence of different substituent groups on cellulosic biodegradability was studied.The oxidized cellulose was buried in soil, and molecular weight was then measured, The change of biodegradability was analysed quantitatively for the oxidized cellulose with defferent DS and different substituent groups,The experimental results show: (1)in the C6 of cellulosic glucose residue, a few number of -COOH (about 3%) was introduced, no influence on cellulosic biodegradability was observed, when -COOH were substituted more (below 15%),the biodegradability was increased.(2) in the C2 and C3 of cellulose glucose residue, dialdehyde group was added suitably (about 10%), the biodegradability of cellulose was enhaned.
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