膦酸改性海藻酸钠基复合材料的制备及其性能研究

发布时间：2018-06-21 16:07

  本文选题：海藻酸钠基 + 复合材料　； 参考：《鲁东大学》2017年硕士论文

【摘要】：由生物形成且富含羧酸阴离子和羟基的海藻酸钠,是最丰富的天然多糖材料之一,凭借优异的生物相容性、生物可降解性、无毒性以及低廉的成本和较强的螯合能力等具有广泛的用途。本文以海藻酸钠SA为基体合成两种截然不同的复合材料。一是采用交联固化的方法复合Fe3+得到粒径约为1.5mm大小的F/A球,二是采用低温酯化的方法复合改性废弃对位芳纶得到P/A颗粒,最后分别用有机膦酸EDTMPA对这两种不同形态的复合材料进行高温酯化改性得到EDTMPA-F/A和EDTMPA-P/A。尤其是合成的EDTMPA-F/A具有双功能、双性能的膦酸改性海藻酸钠基复合材料在水污染治理以及催化合成生物柴油等应用上具有实际意义。通过红外、热重以及扫面电镜等手段对两种材料进行表征,同时探究两种材料的催化及其吸附Pb(Ⅱ)性能。1.首先通过F/A和EDTMPA-F/A平衡催化对比实验结果得到EDTMPA-F/A催化性能更加卓越,接下来围绕EDTMPA-F/A催化实验的单因素条件进行初步探究得到最佳MR值为8:1,EDTMPA-F/A用量为9wt%,温度为90oC;以这三个结论作为催化条件,通过RSM实验设计分析后得到优化的最佳催化条件MR值为6.634:1、EDTMPA-F/A用量为10.76552wt%、温度为81.2713oC,按照该条件进行重复试验三次,实验值均在89%左右。EDTMPA-F/A反复使用3次后,使用效率保持在44%以上。EDTMPA-F/A的催化动力学方程为:r=2.17×10-2exp(-10.25/RT)[CA][CB]-2.71×10-3exp(-4.15/RT)[CC][CD]。其次吸附性能的探究从F/A和EDTMPA-F/A静态饱和吸附对比实验表明,两种材料对多种常见金属离子均具有吸附效果,而EDTMPA-F/A对Pb(Ⅱ)的吸附效果尤为显著,接下来以EDTMPA-F/A为主对吸附条件进行探究得到吸附最佳pH值为3.5以及EDTMPA-F/A剂量为0.0150g时,EDTMPA-F/A吸Pb(Ⅱ)效率最高。通过与经典的吸附模型拟合,得到EDTMPA-F/A的吸附过程为边界层扩散控速同时主要受粒内扩散的影响,整个过程吸热而且界面混乱度变大。2.EDTMPA-P/A吸附性能的研究过程通过EDTMPA-P/A和P/A静态饱和吸附对比实验验证吸附Pb(Ⅱ)性能显著而且EDTMPA-P/A优于P/A。接下来围绕EDTMPA-P/A吸附Pb(Ⅱ)的实验条件进行初步探究得到Pb(Ⅱ)溶液的pH=4和EDTMPA-P/A的剂量为0.0150g时,吸Pb(Ⅱ)效率最高。EDTMPA-P/A吸附动力学曲线在2h内达到平衡,为化学吸附中螯合配位控速,同时主要受液膜扩散的影响,整个过程吸热而且界面混乱度变大。同时在二元离子体系中,EDTMPA-P/A吸Pb(Ⅱ)性能卓越。用pH=1的HNO3溶液洗脱EDTMPA-P/A的洗脱率较高,在循环两次使用后,洗脱率仍在70%以上。通过RSA构建新的三元二次回归模型,优化实验因素得到pH值为3.21、EDTMPA-P/A用量为20.1876mg、初始Pb(Ⅱ)浓度为1.642mmol/L为最佳吸附条件,按照该条件进行重复试验三次,实验Q值均在191.63mg/g左右,稳定性好。
[Abstract]:Sodium alginate, which is biologically formed and rich in carboxylic acid anions and hydroxyl groups, is one of the most abundant natural polysaccharides, with excellent biocompatibility and biodegradability. Non-toxic, low cost and strong chelating ability have a wide range of applications. In this paper, two different composite materials were synthesized with sodium alginate SA as matrix. One is to synthesize Fe _ 3 by crosslinking and solidification to obtain F- / A ball with the size of 1.5mm, and the other is to compound the modification of waste para-aramid by low temperature esterification to get P- / A particles. Finally, EDTMPA-F / A and EDTMPA-P / P / A were prepared by esterification of EDTMPA-F / A and EDTMPA-P / A respectively with EDTMPA. Especially the synthesized EDTMPA-F / A has dual functions and double performance phosphonic acid modified alginate matrix composites have practical significance in water pollution control and catalytic synthesis of biodiesel. The two materials were characterized by infrared, thermogravimetric and scanning electron microscopy, and their catalytic properties and adsorption properties of Pb (鈪，

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