低分子量N,O-羧甲基壳聚糖的合成及吸湿保湿性能

Moisture-adsorption and retention capacity of low molecular weight N,O-carboxymethyl-chitosan

采用不同反应温度、反应时间和低分子量壳聚糖与氯乙酸摩尔比,在非均相反应体系中合成了不同取代度的低分子量N,O-羧甲基壳聚糖。当反应温度为60°C,反应时间为4h,低分子量壳聚糖与氯乙酸投料比为1∶1.5时,目标产物的取代度可达71%。吸湿保湿性能测定表明:取代度越大,低分子量N,O-羧甲基壳聚糖的吸湿保湿性越好,在相对湿度为81%,取代度从27%增大到71%时,其吸湿性从32.14%增大到37.27%,保湿性从310.72%增大到348.69%。

Low molecular N, O - carboxymethyl - chitosans with different degrees of substitution were synthesized under heterogeneous conditions by controlling the reaction temperature, the reaction time and the molar ratio of low molecular weight chitosan to chloroacetic acid. The result showed that when the reaction temperature was 30℃, the reaction time was 8h, and the molar ratio of low molecular weight chitosan to chloroacetic acid was 1： 1. 5, the detree of substitution of preducts reached up to 71%. The moisture - adsorption and - retention capacity of low molecular weight N, O - carboxymethyl - chitosans with different degree of substitution were investigated. The results indicated the moisture - adsorption and retention capacities of low molecular weight N, O- carboxymethyl- chitosan were increased with the increase of the degree of substitution. At the relative humidity 81%, the moisture - adsorption and - retention capacity of low molecular weight N, O- carboxymethyl - chitosan increased from 32. 14% to 37. 27% and from 310. 72% to 348. 69%, respectively, with the increase of the degree of substitution from 27% to 71%.