硫脲树脂的合成及其对金属离子的吸附性能

Synthesis of Thiourea Resins and Their Adsorption for Metal Ions

采用双(异硫氰酸甲酸)丁二酯分别与二乙烯三胺、三乙烯四胺、四乙烯五胺、多乙烯多胺单体进行加聚反应制得4种主链上含有硫脲基团的新型螯合树脂PETU-Ⅰ～PETU-Ⅳ。红外光谱分析表明,树脂中存在硫脲基团,树脂热稳定性和溶胀性能良好。用静态吸附法研究了PETU树脂对金属离子的吸附性能,4种树脂对Au(Ⅲ)的吸附容量分别为2.48、2.68、4.74和6.44mmol/g,对Ag(Ⅰ)的吸附容量分别为2.15、3.53、3.74和3.98mmol/g,对Cu(Ⅱ)、Zn(Ⅱ)等金属离子吸附容量低于0.36mmol/g;PETU-Ⅳ对Au-Cu和Au-Zn的分离因子>1000,PETU-Ⅱ对Ag-Cu和Ag-Zn的分离因子>10,说明树脂对Au(Ⅲ)、Ag(Ⅰ)具有较高的吸附容量和优良的吸附选择性。PETU-Ⅳ树脂重复使用5次,吸附容量无明显下降,说明树脂具有良好的重复利用性能。

Chelating resins with thiourea groups in their main chains （ PETU- Ⅰ - PETU-Ⅳ） were obtained the polyaddition of butyl bis（ alkoxy carbonyl isothiocyanate） with diethylene triamine, triethylene tetraamine, tetraethylene pentamine, and polyethylene polyamine respectively. FTIR results show that the resins contain thiourea groups, and the resins show good thermal stability and swelling property. The adsorption of metal ions on PETU was investigated by batch tests. Adsorption capacities of the 4 kinds of resins for Au （ Ⅲ ） are 2. 48, 2. 68, 4. 74 and 6. 44 mmol/g respectively, those for Ag （ Ⅰ ） are 2. 15, 3.53, 3.74 and 3.98 mmol/g respectively, and those for other ions such as Cu（ Ⅱ ） and Zn（ Ⅱ ） were below 0. 36 mmol/g. The separation factors of PETU-Ⅳ for Au-Cu and Au-Zn are above 1 000, and that of PETU- Ⅱ for Ag-Cu and Ag-Zn are above 10, which justifies that PETU shows excellent adsorption and selectivity performance for Au （ Ⅲ ） and Ag（ Ⅰ ）. The adsorption capacities of PETU decreased little in five adsorption-desorption cycles, which showed that PETU had good regeneration properties.