含咪唑啉基偕胺肟化聚合物合成及其对Cu(Ⅱ)吸附性能

Synthesis of Amidoxime Modifided Polymer Containing Imidazolinyl and Its Adsorption Performance for Cu(Ⅱ)

以丙烯酰胺（AM）、丙烯腈（AN）、1-（2-N-烯丙基氨乙基）-2-油酸基咪唑啉（NIPA）为原料，制备了咪唑啉基偕胺肟化聚合物AM／AO／NIPA。对其进行了FTIR、SEM和TG表征。通过静态吸附实验考察了pH、吸附时间、溶液初始浓度对聚合物AM／AO／NIPA和吸附剂聚丙烯酰胺（PAM）吸附低浓度Cu2＋过程的影响，并探讨了吸附机理。结果表明：聚合物AM／AO／NIPA的Cu2＋吸附容量受溶液pH影响不大；当聚合物AM／AO／NIPA加入量为0．05g时，在30℃、pH=5、吸附3h后，对Cu2＋质量浓度为100mg／L的溶液吸附达到平衡，此时吸附容量为37．32mg／g；整个吸附过程符合准二级动力学模型，以化学吸附为主；对Langmuir和Freundlich等温吸附模型均能较好拟合。通过Langmuir模型拟合计算得到，偕胺肟化聚合物AM／AO／NIPA的Cu2＋饱和吸附量为267．38mg／g，是相同条件下吸附剂PAM饱和吸附量的3倍以上。ANUAO／NIPA循环使用4次后，吸附量保留率高达92．99％。

Amidoxime modified polymer containing imidazolinyl （AM/AO/NIPA） was synthesized by using acrylamide （AM）, acrylonitrile （AN） and 1-（2-N-allyl ammonia ethyl）-2-oleic acid imidazole （NIPA） as raw materials. The resultant product was characterized by FTIR, SEM and TG. Subsequently, the static adsorption experiments were used to investigate the effects of pH value, adsorption time, and initial concentration of solution on the adsorption capability of AM/AO/NIPA and polyacrylamide （PAM） for low concentration Cu2＋, respectively. Finally, the adsorption mechanism was discussed. The results showed that the adsorption capacity of AM/AO/NIPA for Cu2＋ was not affected by the pH value of the solution. When the additive amount of AM/AO/NIPA was 0.05 g and the adsorption was performed at 30 ℃, pH 5 and 100 mg/L initial concentration of Cu2＋, the equilibrium was reached at 3 h, and the adsorption capacity of Cu2＋ was 37.32 mg/g. The pseudo-second-order kinetic model could well describe the adsorption process, and the chemical adsorption controlled the whole adsorption rate. Both Langmuir and Freundlich isotherm models were fitted well to the experimental data. Through the fitting calculation, the maximum adsorption capacity of AM/AO/NIPA for Cu2＋ was 267.38 mg/g, which was three times higher than that of PAM. Furthermore, the amidoxime polymer AM/AO/NIPA exhibited an excellent cycling stability of four cyeles with 92.99% capacity retention.