巯基酯化壳聚糖的合成及对Cd^(2+)的去除性能研究

Synthesis of sulfhydryl esterification chitosan and research on removal performance of Cd^(2+)

采用化学方法,研究了以巯基甲壳质制备巯基酯化壳聚糖的最佳合成方案。研究表明,巯基甲壳质的脱乙酰条件(包括时间、温度、氢氧化钠浓度)影响其产物巯基酯化壳聚糖对重金属镉离子的吸附效果。当脱乙酰时间为2 h,温度为160℃,氢氧化钠浓度为20%时,20 mg的合成产物对30 mL Cd2+浓度为20 mg/L水样的去除率最高,达到85.46%,其对镉离子的吸附量达到28.5 mg/g。通过对产物进行红外分析发现,巯基甲壳质中出现脂基特征峰值,脱乙酰后脂基并没有消失,证明最后的产物为巯基酯化壳聚糖。

By using the chemical modification methods, we researched the best synthetic scheme for sulf- hydryl esterification of chitosan. The research shows that the deacetylation conditions （including time, tempera- ture and NaOH concentration） of sulfhydryl chitin have an effect on adsorption effect of heavy metal cadmium ion which is adsorbed by the sulfhydryl esterification of chitosan. In the process of deacetylation, when the time is 2 h, the temperature is 160℃ , sodium hydroxide concentration is 20% , the 20 mg synthesis removal rate for 30 mL Cd2＋ concentration of 20 mg/L water is highest, reaching to 85.46%. The adsorption of cadmium ions is 28.5 mg/g. Through infrared analysis of the products, it is found that there is a characteristic peak of ester groups in sulfhydryl chitin, and the ester group does not disappear after deacetylation. This shows that the final product is sulfhydryl esterification of chitosan.