HPCS-AM-DAC共聚物的合成及絮凝性能研究

Synthesis of HPCS-AM-DAC and its Flocculating Properties

摘要:

以羟丙基壳聚糖（HPCS）、丙烯酰胺（AM）、丙烯酰氧乙基三甲基氯化铵（DAC）为原料合成三元高分子共聚物（HPCS-AM-DAC）。采用红外光谱（FTIR）、核磁共振氢谱（1HNMR）、X射线衍射（XRD）、扫描电镜（SEM）对其结构和形貌进行了表征。考察了反应温度、硝酸铈铵用量、单体滴加时间及DAC用量对产物阳离子度及特性黏数的影响。结果表明：在水用量为25 mL，丙烯酰胺用量为2 g，HPCS 用量为1 g，反应温度70℃，引发剂用量为（占HPCS质量分数）1.7%，单体滴加时间为35 min，DAC用量为3.5 g的条件下，产物的阳离子度和特性黏数均达到较佳值，分别为63.01%和468.81 mL/g。采用壳聚糖（CTS）、HPCS、HPCS-AM-DAC及市售阳离子聚丙烯酰胺（CPAM）对高岭土模拟废水进行絮凝实验，考察了絮凝体系pH，不同絮凝产品投加量对浊度去除率的影响，结果表明，在浊度为200 NTU的高岭土模拟废水中， HPCS-AM-DAC共聚物絮凝的适宜pH为2~6，适宜投加量为2~5 mg/L，在此条件下浊度去除率均在96%以上。通过对上清液Zeta电位、絮体粒径及絮体XPS分析可知，HPCS-AM-DAC对高岭土模拟废水絮凝机理为电性中和与吸附架桥协同作用。

Abstract:

In this paper,hydroxypropyl chitosan(HPCS),acrylamide(AM) and acryloyloxyethyltrimethylammonium chloride (DAC) were used as raw materials to synthesize the HPCS-AM-DAC. The structures and morphologies of the compounds were characterized by FTIR, 1HNMR, XRD and SEM. The influences of reaction temperature, Ammonium nitrate dosage, monomer dropping time and DAC dosage on cationic degree and intrinsic viscosity were investigated.The results showed that under the conditions of H2O 25 mL, AM dosage 2 g, HPCS dosage 1 g, reaction temperature 70℃, initiator dosage 1.7% (based on the mass of HPCS, the same below), dropping time of monomers 35 min, and DAC dosage 3.5 g, both cationic degree and intrinsic viscosity of the product reached a good value of 63.01% and 468.81 mL/g. The flocculation experiments of kaolin simulated wastewater were carried out with CTS, homemade HPCS, HPCS-AM-DAC and commercial cationic polyacrylamide (CPAM). The effect of flocculation system pH and flocculation dosage on the removal rate of turbidity was investigated.In kaolin simulated wastewater with a turbidity of 200 NTU， the results showed that the suitable pH range for flocculation of HPCS-AM-DAC was 2~6, and the dosage range was 2mg/L~5mg/L.Under these conditions, the turbidity removal rate is above 96%. Based on the zeta potential, floe particle size and flocculation XPS analysis, the flocculation mechanism of HPCS-AM-DAC on simulated kaolin wastewater is the synergistic effect of electrical neutralization and adsorption and bridging.