优化等离子参数制备PP基功能纤维及其对Pb^(2+)的吸附性能

Preparation of PP-based functional fiber by optimizing plasma parameters and its adsorption performance for Pb^(2+)

为进一步扩展熔喷聚丙烯(PP)纤维在废水重金属离子去除领域的应用,通过低温等离子技术用甲基丙烯酸缩水甘油酯(GMA)改性PP纤维得到PP接枝GMA(PP-g-GMA)纤维,探讨等离子体处理工艺参数对接枝效果的影响,继而胺化制备螯合纤维,借助红外光谱进行表征。考察溶液pH、吸附时间、初始浓度、共存离子和再生对螯合纤维吸附Pb^(2+)效果的影响。结果表明:将GMA单体接枝到熔喷PP纤维表面时,等离子体放电功率15 W、气氛压强20 Pa、放电时间3 min时最佳,接枝率最大,为6.4%;以水/N,N-二甲基甲酰胺为溶剂,二乙烯三胺(DETA)与GMA发生开环胺化反应;红外光谱分析表明成功地接枝了GMA和引入胺基。在Pb^(2+)初始质量浓度40 mg/L、pH=5、120 min时,PP-g-GMA-DETA螯合纤维对Pb^(2+)的吸附量达到最大,为31.87 mg/g;吸附过程符合准二级动力学模型,吸附等温线符合Langmuir等温吸附模型。共存离子对螯合纤维吸附Pb^(2+)影响不大,且纤维具有良好的再生性能。

To further expand the application of melt-blown polypropylene(PP)fiber in wastewater field of heavy metal ion removal,PP fiber was modified with glycidyl methacrylate(GMA)by low temperature plasma to obtain PP-grafted-GMA(PP-g-GMA)fibers.The effects of plasma parameters on grafting were investigated,and then the chelating fiber was prepared after amination and characterized by infrared spectrum.The effects of solution pH,adsorption time,initial concentration,coexistence ions and regeneration on the adsorption of Pb^(2+) by chelating fiber were discussed.Results showed that when GMA monomer was grafted to melt-blown PP fiber surface,the best plasma parameters were discharge power of 15 W,atmospheric pressure of 20 Pa,discharge time of 3 min,and the grafting rate was the largest(6.4%).Using water/N,N-dimethylformamide as solvent,the ring-opening amination reaction of diethyltriamine(DETA)and GMA was occurred.Infrared spectrum analysis showed that GMA was successfully grafted and amino groups were introduced.The adsorption capacity of PP-g-GMA-DETA chelating fiber for Pb^(2+) reached the maximum of 31.87 mg/g at the initial mass concentration of 40 mg/L,pH=5 and 120 min.The adsorption process followed the quasi second-order kinetic model,and the adsorption isotherm conformed to the Langmuir isothermal adsorption model.Coexisting ions had little effect on the adsorption of Pb^(2+) by chelating fiber,and the fiber had good regeneration performance.