反相乳液聚合法制备HACC及其絮凝性能研究

The Synthesis of HACC by Inverse Emulsion and its Flocculation Study

摘要:

以壳聚糖（CTS）和2,3-环氧丙基三甲基氯化铵（GTA）为原料，用反相乳液聚合法合成了壳聚糖季铵盐（HACC）。并采用红外光谱（FTIR）、核磁共振氢谱（1HNMR）、环境扫描电镜图（ESEM）和X-射线衍射图（XRD）对其结构和形貌进行表征。详细考察了反相乳液体系中复合乳化剂的HLB值、油水体积比、引发剂用量、时间、温度和m（GTA）:m（CTS）对反应取代度以及产率的影响。结果表明合成HACC的最佳工艺条件为：复合乳化剂的HLB=6.0、油水体积比1:1、引发剂用量为GTA质量的1.5%，反应时间为5 h，温度为60 ℃，m（GTA）:m（CTS）=3.0。在此条件下产物的取代度和产率均达最大值，分别为1.331和81.16%。使用原料CTS、自制HACC和市售絮凝剂阳离子聚丙烯酰胺（CPAM）对高岭土模拟废水进行絮凝实验。研究了絮凝体系pH、絮凝剂投加量对絮凝效果的影响。实验结果表明，CPAM、CTS和HACC对高岭土模拟废水都具有较好的絮凝效果，HACC适宜的絮凝pH值为6，絮凝剂的最佳投加量为1 mg/L。在相同条件下絮凝效果HACC优于CTS和CPAM。

Abstract:

Chitosan quaternary ammonium salt(HACC) was synthesized by reaction of chitosan(CTS) with 2,3-trimethyl ammonium chloride(GTA) via inverse emulsion polymerization. The structure of HACC was characterized by Fourier transform infrared spectrum(FTIR), nuclear magnetic resonance hydrogen spectrum((1HNMR), environmental scanning electron microscope(ESEM) and X-ray diffraction(XRD). In addition, the effect of HLB, volume ratio of oil to water, the amount of initiator, reaction time, temperature and m(GTA):m(CTS) on degree of substitution(DS) and yield(P) were investigated. The results indicated that the optimal processing for the preparation of HACC were as follows: HLB=6.0, volume ratio of oil to water is 1:1, amount of initiator is 1.5%, reaction time is 5h, temperature is 60℃, m(GTA):m(CTS)=3.0. The products has highest DS and P, DS=1.331, P=81.16%. Moreover, flocculation experiment employed kaolin suspension as synthetic wastewater and the cationic polyacrylamide(CPAM), CTS and HACC as flocculant, the effects of flocculant dosage and pH of wastewater on result were investigated, respectively. It was indicated that CPAM, CTS and HACC has good flocculation effect on kaolin suspension. The appropriate flocculation of HACC were as follows: the optimum flocculation pH=6, best dosage of flocculant dosage is 1 mg/L. And under the same conditions, HACC possessed better flocculating performances than CTS and CPAM.