微波辐照下羧甲基纤维素的制备

Synthesis of CMC Under Microwave Irradiation

本文以棉纤维及纸浆为原料在微波辐照下制备CMC ,通过测定其取代度考察该反应的反应条件 ,如反应物一氯乙酸的量及NaOH的量对该反应的影响 ,同时本文也考察了微波辐照对制备CMC反应的影响。结果表明 ,反应物一氯乙酸不易过量 ,但反应体系中要保持一定的游离碱的浓度才能得到高取代度的CMC ;短时间的微波辐照不仅有利于纤维素的醚化反应和碱化反应 ,同时也大幅度提高了产物的取代度。微波辐照对聚合度较小的纸浆的影响比棉纤维要大 ,更有利于制备高取代度的CMC。

In this paper,CMC with high DS was synthesized under microwave irradiation by fine cotton or pulp as raw material.It is charactered that the effect of reaction conditions,such as the quantities of chloroacetic acid and NaOH on the product by testing DS.In order to get CMC with high DS,the quantities of chloroacetic acid is not excessive,however,in the reaction system the quantities of NaOH is high so as to maintain the concentration of free NaOH.When the reaction carried out under microwave irradiation,the microwave irradiation affected not only on the etherification,but also on mercerization.The results shown that the DS of the product was raised greatly by the microwave irradiation,especially for pulp as raw material,whose molecular weight is smaller to that of cotton,the product with high DS was got under microwave irradiation.