Abstract:

Chitosan was modified by chloroacetic acid，acrylic acid and 2,3-epoxypropyl trimethyl  ammonium chloride to obtain amphoteric carboxymethyl-quaternary ammonium chitosan（CMQAC）and amphoteric carboxyethyl-quaternary ammonium chitosan（CEQAC），then the structures of the products were confirmed by IR，¹H NMR and XRD. The performance of scaling inhibition of amphoteric chitosan derivatives with respect to CaSO₄ were evaluated by static antiscaling experiment，and the results showed that the inhibition rate could be up to 100% when the dosage of  amphoteric chitosan derivatives was 16 mg/L，[Ca²⁺]<2000 mg/L and [SO₄^2－]<4800 mg/L. The bacterial inhibition of amphoteric chitosan derivatives with different degrees of substitution（DS）of quaternary ammonium was measured with the vial method. The results showed that the sterilizing rates can be up to 99.7% and 99.2% with chitosan derivative addition of 30mg/L when the DS of quaternary ammonium was 0.73 and 0.50 respectively for CMQAC and of CEQAC. The modification resulted in a great improvement in scaling inhibition and bacterial inhibition of chitosan derivatives in comparison with chitosan.

摘要：

采用氯乙酸、丙烯酸和2,3-环氧丙基三甲基氯化铵对壳聚糖（CTS）改性，制得羧甲基-季铵壳聚糖（CMQAC）和羧乙基-季铵壳聚糖（CEQAC），并通过IR、¹H NMR、XRD对产物进行了结构确证。用静态阻垢的方法对两性壳聚糖衍生物阻硫酸钙垢的性能进行了评价，结果表明两性壳聚糖用量为16 mg/L、[Ca²⁺]<2000 mg/L、[SO₄^2－]<4800 mg/L时，阻垢率可达到100%。用小瓶测试法测定不同季铵取代度（DS）的两性壳聚糖对异养菌的杀菌效果。研究结果表明，在用量为30 mg/L时，CMQAC季铵取代度为0.73时杀菌率为99.7% ，CEQAC季铵取代度为0.50时杀菌率为99.2%，改性后壳聚糖衍生物的阻垢和杀菌性能与壳聚糖相比有了明显提高。