光氯化—烷基化两步法制备超高交联树脂及其对苯酚的吸附研究

发布时间：2018-08-09 16:51

【摘要】：超高交联吸附树脂凭借其优良的孔结构、高比表面积、高机械强度、优异的吸附选择性且容易脱附再生等特点,成为吸附分离新材料的研究热点,但传统超高交联树脂骨架结构单一(多为St-DVB型)、制备成本较高的缺点也在某种程度上限制了它们的应用领域的拓宽。本研究是在实验室前期工作基础上,首次采用对二甲苯侧链光氯化及持续Friedel-Crafts烷基化聚合反应合成了一类超高交联树脂,并研究了其对水溶液中苯酚的静态吸附特性。超高交联树脂具体的制备过程分为两步,一是由对二甲苯侧链光氯化反应制备混合氯代对二甲苯,以制得对二氯苄含量最高的混合氯代对二甲苯；二是在FeCl3催化作用下,将制得的氯代对二甲苯自聚、或者与苯BE(或联苯DP)共聚制备超高交联树脂。通过红外光谱仪、元素分析仪、比表面积和孔径测定仪等对该类超高交联树脂的化学结构、比表面积及孔结构等进行表征,并对其合成机理进行初步探讨。实验结果表明：该类吸附树脂具有比表面积高(最高可达905 m2/g)、孔体积大、孔径分布窄(主要分布在微孔和低端中孔)等特点,而且此类树脂中都含有O元素,这是残留在树脂中的CI被水解成-OH或者被氧化为-C=O而来。通过对苯酚的静态吸附行为的研究表明,在研究的浓度范围内,此超高交联树脂对苯酚的吸附量高达171mg/g,明显优于国内外用于酚类吸附的Amberlite XAD-4树脂；对苯酚的吸附等温线能很好的用Freundlich和Langmuir方程拟合；在吸附过程中,吸附剂中的羟基与苯酚的酚羟基形成氢键作用力,这增加了树脂对苯酚的吸附量；动力学研究表明吸附过程符合准二级动力学模型；吸附过程是自发的放热过程。这类树脂有望在酚类废水处理中得到应用。
[Abstract]:Ultra-high crosslinking adsorption resin has become the research focus of new materials for adsorption and separation because of its excellent pore structure, high specific surface area, high mechanical strength, excellent adsorption selectivity and easy desorption regeneration. However, the traditional ultra-high crosslinked resin skeleton structure is single (mostly St-DVB type), and the high cost of preparation also limits their application field to some extent. Based on the previous work in laboratory, a kind of super crosslinked resin was synthesized by photochlorination of p-xylene side chain and continuous Friedel-Crafts alkylation polymerization for the first time, and its static adsorption properties for phenol in aqueous solution were studied. The specific preparation process of ultrahigh crosslinked resin is divided into two steps. One is the preparation of mixed p-chlorobenzene by photochlorination of p-xylene side chain to prepare p-dichlorobenzene mixed p-xylene with the highest content of p-dichlorobenzene, and the other is under the catalysis of FeCl3. The super crosslinked resin was prepared by self-polymerization of p-xylene chloride or copolymerization with benzene be (or biphenyl DP). The chemical structure, specific surface area and pore structure of this kind of super crosslinked resin were characterized by infrared spectrometer, element analyzer, specific surface area and pore size analyzer, and the synthetic mechanism was preliminarily discussed. The experimental results show that the adsorption resins have high specific surface area (up to 905 m2 / g), large pore volume and narrow pore size distribution (mainly distributed in micropores and low-end mesoporous). The residual CI in the resin is hydrolyzed to-OH or oxidized to Con O. The static adsorption behavior of phenol shows that the adsorption capacity of this super crosslinked resin for phenol is as high as 171 mg / g in the range of concentration studied, which is obviously superior to the Amberlite XAD-4 resin used for phenol adsorption at home and abroad. The adsorption isotherm of phenol can be fitted well by Freundlich and Langmuir equation. In the process of adsorption, the hydroxyl group in adsorbent forms hydrogen bond force with phenol hydroxyl group, which increases the adsorption capacity of phenol. The kinetic study shows that the adsorption process accords with the quasi-second-order kinetic model and the adsorption process is a spontaneous exothermic process. This kind of resin is expected to be used in phenolic wastewater treatment.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：O647.31

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