DS≥0.8的羧甲基淀粉钠的研制

SYNTHESIS OF CARBOXYMETHYL STARCHES WITH DS≥0.8

以溶媒法合成了DS 0.8—1.1的羧甲基淀粉钠。重点考察了配料比、体系中水分含量、反应时间、温度及后处理对产品取代度的影响。结果表明,当淀粉量一定时,氢氧化钠与氯乙酸配比是氯乙酸合理利用的关键,也是影响取代度的关键因素。

Increasing degree of carboxymethyl substitution(DS) in some extent leads to enhancing filtration-loss controlling, salt-tolerency, and heat resistancy of carboxymethyl starches (CMSc)as a mud additive. In this work the synthesis of CMSs with DS 0.8-1.1 by a solvent process is presented, and the effects of ratios of components in carboxymethylation, water content in reaction mixture, time and temperature of reaction, and post treatment on DS value of resulting products are investigated. The key factor both in increasing DS and in properly utilizating chloroaceticacid is shown to be the ratio of NaOH to chloroacetic acid for certain amount of starch. The pH and salt content of ultimate products exert influence on DS values determined.