由于壳聚糖的大分子键上分布着大量的氨基、 羟基和N-乙酰基等活性功能基团, 将其改性作为天然绿色絮凝剂越来越受到关注, 但对其的接枝共聚产物的光谱学表征研究鲜有报道。 因此, 对壳聚糖基絮凝剂进行光谱学表征与分析研究具有重要意义。 论文以壳聚糖(CS)、 丙烯酰胺(AM)、 二甲基二烯丙基氯化铵(DMDAAC)为接枝共聚单体, 采用光聚合技术制备壳聚糖基絮凝剂CS-P(AM-DMDAAC)。 采用X射线衍射(XRD)、 紫外光谱(UV)、 红外光谱(IR)研究其结构特征； 分析了壳聚糖、 丙烯酰胺、 二甲基二烯丙基氯化铵及三者接枝共聚产物的X射线衍射(XRD)、 紫外光谱(UV)、 红外光谱(IR)的图谱特征和振动吸收峰归属。 研究了壳聚糖脱乙酰度、 壳聚糖浓度、 阳离子度对接枝共聚产物壳聚糖基絮凝剂CS-P(AM-DMDAAC)的X射线衍射(XRD)、 紫外光谱(UV)、 红外光谱(IR)的影响。 UV光谱和IR光谱研究结果证明CS, AM和DMDMAAC成功发生接枝共聚反应制备出CS-P(AM-DMDAAC), 壳聚糖浓度增加导致其光谱对称性减弱。 XRD图谱研究表明接枝共聚反应使得壳聚糖的晶型结构趋向不定型结构转变, 不定型结构相比于晶型结构更易于水化, 故接枝共聚产物具有更加优异的溶解性。

Since there were a lot of amino, hydroxyl, and N- acetyl reactive functional groups distributed on the chitosan macromolecule chains. The modification of chitosan as natural green flocculants had received more and more attentions, but the graft copolymer product thereof spectroscopic characterizations were rarely reported. Therefore, the spectroscopic characterization and analysis of the chitosan-based flocculants were of great significance. The chitosan based flocculant CS-P(AM-DMDAAC) was synthesized by photopolymerization method using chitosan (CS), acrylamide (AM), and diallyl dimethyl ammonium chloride (DMDAAC) as the monomers of graft copolymerization. X-ray diffraction (XRD), Ultraviolet spectroscopy (UV), and Infrared (IR) spectroscopy were applied to investigate the structural characteristics of CS-P(AM-DMDAAC). The characteristic of spectrum and the attributions of characteristic absorption peaks of CS, AM, DMDAAC, and CS-P(AM-DMDAAC) were analyzed by the X-ray diffraction (XRD), ultraviolet spectroscopy (UV), and infrared spectroscopy (IR). The effects of degree of deacetylation of chitosan, concentration of chitosan, cationic degree of graft copolymer on X-ray diffraction (XRD), Ultraviolet spectroscopy (UV), and Infrared (IR) spectrum of CS-P (AM-DMDAAC) were systematically investigated. Ultraviolet spectroscopy (UV) and Infrared (IR) spectrum demonstrated that AM and DMDMAAC were successfully grafted onto CS to prepare CS-P (AM-DMDAAC). The increase of chitosan concentration led to weakening spectrum symmetry. X-ray diffraction showed that the crystal structure of chitosan was transformed into amorphous structure by the graft copolymerization. Compared with the amorphous structure, the crystal structure was more easily hydrated, so the graft copolymer product had more excellent solubility.