【作者】 陆中旭；

【导师】 彭奇均；

【作者基本信息】 江南大学 ， 应用化学， 2008， 硕士

【摘要】 工业的发展,环境污染的加剧,人类赖以生存的食品,饮用水中过多的重金属对人类的伤害越来越明显。本文提出从苯乙烯系树脂出发,制备螯合树脂去除重金属离子的方法,该法具有设备简单、占地面积小、可富集金属使水得到重复循环利用,不产生二次污染的优点。本文通过Friedel-Crafts反应,以苯乙烯—二乙烯苯聚合物为载体自制乙酰化交联聚苯乙烯微球,再经Mannich反应法,制备了新型胺基树脂,避免了氯甲基化法使用氯甲醚等致癌物质带来的弊端。再由胺基树脂出发,制备出氨基膦酸型螯合树脂,并对重金属离子铅进行静态吸附,测定研究树脂的吸附性能、再生效果。文中讨论了反应温度和时间、物料比等因素对各部反应的影响并对机理进行探讨。在自制乙酰化交联聚苯乙烯微球过程中,当反应时间为3小时,三氯化铝与苯乙烯树脂的摩尔比为2.5,乙酸酐与苯乙烯树脂质量比2时,产物乙酰基团的取代度可到65%左右。同时对产物乙酰化程度进行红外定量分析方法研究。乙酰化交联聚苯乙烯微球胺化反应中,当胺和乙酰基的摩尔比例为:10:1,胺和多聚甲醛摩尔比为:1:1,胺和盐酸的摩尔比例为:4:1,反应时间9h,反应温度60℃时,产物的增重率可达80%左右。对数据作出回归分析得出方程,以便给所需要的特定胺化率树脂设定反应条件。氨基膦酸树脂的制备中,当亚磷酸与NH2摩尔比8:1,甲醛与NH2摩尔比8:1,盐酸与NH2摩尔比2:1,反应温度为70℃,反应时间为10h时,产物的氨基转化率达到90%左右。对各反应参数的数据分析,找到了一些重要的影响条件及其与产物氨基转化率之间线性关系。通过螯合树脂对重金属铅的吸附及解吸,看出树脂对浓度在0~1mg/L范围内铅的吸附不容易进行。功能基含量为1.64mmol/ g的树脂对铅的静态饱和吸附后,功能基与铅的摩尔比为1:0.009,近似于100:1。但树脂解吸效果很好,用0.3mol/l盐酸做洗脱剂,最大洗脱率可达99%左右。更多还原

【Abstract】 With industrial developing and the worsening environmental pollution, the heavy metals in foods and the drinking water which people feed on have injured the health more obviously. The article gives the preparation of chelating resin which is from acetylated polystyrene micro-beads.The chelating resin can reduce the quantities of heavy metals.The method is of simple equipment, small occupy area and also make water be used repeatly by metal enrichment with no second pollution.In this paper, the new amino resin was prepared from acetylated polystyrene micro-beads, formaldehyde and tetraethylene pentamine by Mannich reaction, which can substitute anion-exchange resin prepared from chloromethyl polystyrene resin which used chloromethyl methylether as reactant, that is strong carcinogen due to methylene bridge exists in the chloromethyl polystyrene. Then the amino methylene phosphonic acid resin was prepared from the new amino resin. The static adsorption and the regeneration character of the resin for Pb2+ were preliminary studied.Influencing factors were discussed such as time and temperature of the reaction, molar ratio of materials and so on. Their mechanism was also discussed in the paper. In the process of preparing acetylated polystyrene micro-beads, the optimum experimental conditions were as follows: AlCl3 : polystyrene(molar ratio)=2.5:1, acetic anhydride : polystyrene(mass ratio) =2:1, reaction time=3 hours. The maximum loading of the acetyl polystyrene could be about 65%. Substituted PS was quantified by infrared spectrum analysis from which we got absorbance of several characteristic peaks.After the new amino resin was prepared, the mass-gain rate of products may reach at 80% in the following reaction conditions. Amine: formaldehyde: hydrochloride: Acetyl=10:10:2.5:1, reaction temperature=60℃and reaction time=9 hours. The certain equation was provided by the regression analyzed data. So we can get the resin which has the given rate of amination by the equation in the future.In the process of preparing amino methylene phosphonic acid resin, the amino-transferring of products may reach at 90% in the following conditions, such as phosphorous acid: formaldehyde: hydrochloride: amino=8:8:2:1, reaction temperature =70℃and reaction time=10 hours. The data of each reaction condition have been analysed and we found more important influence conditions and the linear relationship between conditions and amino-transferring of products.The static adsorption and the regeneration character of the resin for Pb2+ was studied. It shows that when the low concentration of Pb2+ varies from 0 to 1mg/L, the adsorption is difficult. When amino phosphonic acid chelating resin loading 1.64mmo1/g of phosphorous acid groups adsorbs Pb2+ in a saturated adsorption state, the ratio between functional groups and Pb2+ is 1:0.009 near 100:1.But the desorption is more effective, especially using hydrochloric acid (the concentration is 0.3mol/l) as the stripping agent. Its stripping ratio is about 99%.更多还原