吡虫啉分子印迹聚合物的制备及性能表征"

Preparation and characterization of imidacloprid molecular imprinted polymers

以吡虫啉为模板分子,丙烯酸(AA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,甲醇为溶剂,悬浮聚合法制备吡虫啉分子印迹聚合物。采用正交分析确定优化合成配方为吡虫啉2 mmol,EDGMA 50mmol,甲醇150 mL,偶氮二异丁腈(AIBN)0.05 g,AA 8 mmol,此时聚合物有较大的饱和吸附量和加标回收率,分别为361 mg/g和94.6%。Scatchard分析表明,所得分子印迹聚合物存在2种不同的结合位点;与非印迹聚合物的吸附性能比较表明,该聚合物对吡虫啉有较好的特异性吸附能力。

Molecular imprinted polymers （MIPs） for imidacloprid were prepared by suspension polymerization method, in which acrylic acid （AA） was used as a functional monomer, and ethylene glycol dimethacrylate（EGD- MA） was used as a crosslinker in methanol. The effects of template molecule, regarding the functional monomer molar ratio, dosage of crosslinkers and solvents on the morphology and adsorption properties were investigated. The opti- mized formula was obtained by an orthogonal test L9 （33） as follows： imidaeloprid 2 mmol, EGDMA 50 mmol, metha- nol 150 mL, AIBN 0.05 g, AA 8 mmol. The results showed that the polymer has largest adsorption capacity （361 mg/g） and recovery ratio （94.6%）. Seatchard analysis showed that there were two kinds of sorption active sites in MIPs, and the binding capacity （Qmax） and dissociation contents （Kd） were Qmaxl = 188.29 rag/g, Kd~ = 16. 42 mg/ L and Qmax2 = 610.08 mg/g, Ka2 --714.29 mg/L respectively. The molecular imprinted polymers exhibited a good se- lectivity and a large adsorption capacity compared to the imidaeloprid materials.