【作者】 袁彦超；

【导师】 陈炳稔；

【作者基本信息】 华南师范大学 ， 高分子物理与化学， 2004， 硕士

【摘要】 本研究旨在开发一种性能良好的新型交联壳聚糖树脂（AECTS）。 采用壳聚糖为原料，甲醛为预交联剂，环氧氯丙烷为交联剂，通过反相悬浮交联法制备出新型壳聚糖树脂，考察了操作条件对合成树脂性能的影响，并用红外光谱、扫描电镜、X射线衍射、热重分析表征其结构。结果表明：甲醛用量、环氧氯丙烷用量、乳化剂用量、搅拌速度、壳聚糖浓度、酸处理条件对树脂性能的影响较大；按最佳合成条件可制备出耐酸性能好、吸附能力强、机械强度好、孔隙率较高的壳聚糖树脂。壳聚糖经交联处理后，结晶能力下降，热稳定性有所降低。 合成了甲醛、环氧氯丙烷交联壳聚糖（AECTS）-Cu、Ni、Co配合物，用FTIR、WXRD、TGA和DSC对配合物进行了结构表征。结果表明：Cu²⁺、Ni²⁺、Co²⁺与AECTS中氨基、羟基发生配位而被吸附；树脂吸附金属离子后，结晶度下降、含水量增加、水的结合牢固程度降低、热稳定性变差、热分解残余物显著增加。对AECTS吸附Cu²⁺、Ni²⁺、Co²⁺的机理、吸附前后材料性能的变化原因和Cu²⁺在树脂中所处的化学环境等进行了深入的分析和讨论。 研究了AECTS对Cu²⁺、Ni²⁺、Co²⁺的吸附热力学行为以及溶液中介质种类的不同对金属离子吸附量的影响。结果表明：AECTS主要以配位形式吸附Cu²⁺和Ni²⁺，以配位形式和物理吸附形式吸附Co²⁺；AECTS对Cu²⁺和Ni²⁺的吸附符合Langmuir等温方程，属于单分子层吸附；AECTS对Co²⁺的吸附同时符合Frundlich模型和Langmuir模型；不同介质对树脂吸附Cu²⁺、Ni²⁺、Co²⁺的影响大小顺序为HCl＞CdCl₂＞MgCl₂＞NaCl，但作用机理差别较大。 测定了不同温度下AECTS自水中吸附苯甲酸的等温线，计算了吸附过程的热力学参数，并用Freundlich方程对实验数据进行拟合，发现该方程适用于所研究的吸附体系。体系的热力学与吸附机理密切相关，当苯甲酸浓度较低时，吸附为放热过程，体系熵减少，降温有利于吸附；当苯甲酸浓度较高时，吸附为吸热过程，体系熵增加，升温有利于吸附。更多还原

【Abstract】 Our aim is to develop a novel type crosslinked chitosan resin (AECTS) withgood properties in this paper.With chitosan as the raw material, a new type chitosan resin was prepared through inverse suspension crosslinking by formaldehyde and epichlorohydrin. The effect of the operating conditions on the properties of the resin was investigated. The structure of the resin was characterized by FTIR, WXRD and TGA. The results revealed that the dosage of formaldehyde, epichlorohydrin and emulsifier, the stirring speed, the chitosan concentration and the treatment conditions with hydrochloric acid affected the properties of the resin largely. A strong-acid-resistance, high-capacity, good-strength, large-porosity chitosan resin was obtained under the optimum reaction conditions. The crystalline grade of crosslinked chitosan reduced and the thermal stability decreased.The complex of AECTS with Cu2+, Ni2+, Co2+ were systhesized and characterized by FTIR, WXRD, TGA and DSC. The results of those analysis showed that the adsorption was realized through binding -NH2 and -OH groups in AECTS with ions. Compared with AECTS, the structure and properties of AECTS-Cu, AECTS-Ni and AECTS-Co had changed. The crystalline grade reduced; The water content increased; The combination firmness degree of water decreased; The thermal stability reduced, and the decomposition residue improved remarkably. In this paper the adsorption mechanism of AECTS with Cu2+, Ni2+ and Co2+, the transformation reason of material performance before and after adsorbing, the chemical environment of ions in AECTS and so on were deeply analysized and discussed.The adsorption thermodynamics properties of AECTS with Cu2+, Ni2+ and Co2+ and the influence of different media on adsorption were studied. The results showed that AECTS adsorbed Cu2+ and Ni2+ mainly by complexation, the experimental data fit well into the Langmuir adsorption isotherm and the process obeyed the formationof monolayer adsorption. AECTS adsorbed Co2+ mainly by complexation and physical style, the experimental data fit well into the Langmuir and Freundlich adsorption isotherm at the same time. The effect order of media was HCl>CdCl2>MgCl2>NaCl, and their effect mechanism differed greatly.The adsorption isotherms of benzoic acid from water onto the novel resin had been determined at different temperatures and the thermodynamic parameters in adsorption process had been calculated. The experimental results fit with Freundlich equations well. The thermodynamics of the systems related closely to the adsorption mechanisms. When the concentration of benzoic acid was low, the adsorption was an exothermal process with the system’s entropy decreasing, and the decrease of temperature did benefit to the process. When the concentration of benzoic acid was high, the adsorption was an endothermal process with the system’s entropy increasing, and the increase of temperature did benefit to the process.更多还原