甲壳素季铵盐的均相合成及絮凝性能研究

Homogeneous Synthesis and Flocculation Properties of Quaternized Chitin

将天然甲壳素直接溶于Na OH/尿素水溶液,以2,3-环氧丙基三甲基氯化铵为醚化剂,均相合成甲壳素季铵盐(QC)。产物用FT-IR、1H NMR、XRD和热分析仪分别进行了表征;并以QC为阳离子型絮凝剂,研究其对蒙脱土悬浮液的絮凝性能,考察了絮凝剂的浓度、絮凝时间、温度和p H值对QC絮凝性能的影响。结果表明:Na OH/尿素水体系下成功均相制备了甲壳素季铵盐,其取代度为0.41,季铵基团的引入明显改变了多糖的聚集态结构和热稳定性能;常温下,当QC浓度为0.5%,絮凝时间为30 min时,其对较宽p H值范围的蒙脱土悬浮液均有较好的絮凝效果,絮凝效率(FE)最高可达98%。

Chitin is dissolved in NaOH/urea aqueous solution at low temperature. Quatemized chitin （QC） was synthe- sized using glycidyl trimethyl ammonium chloride as etherifying agent. The products were characterized by 1H NMR, b-T- IR, XRD and thermal analysis apparatus. The floceulation properties for montmorillonite suspensions （MMT） were stud- ied using QC as cationic flocculant. Factors affecting flocculation properties were investigated respectively,including the flocculant concentration,flocculation time,temperature and pH value. The results showed that QC was successfully pre- pared in NaOH/urea aqueous solution, and the substitution degree （DS） was 0.41. Aggregation structure and thermal stability of polysaccharides were significantly changed because of the introduction of quaternary ammonium groups. When concentration was 0.5% and flocculation time was 30 min, QC had better flocculation effects for MMT in a quite wide range of pH values at room temperature. The highest flocculating efficiency （FE） reached 98%.