椰糠粉/聚丙烯酸-丙烯酰胺复合吸水材料的制备及其吸保水性能

Preparation and Water Absorption/Retention Properties of Coconut Husk Powders/Poly(Acrylic Acid-co-Acryl Amide)Hybrid Superabsorbent

以椰糠粉为基体材料,丙烯酸和丙烯酰胺为单体,N,N-亚甲基双丙烯酰胺(MBA)为交联剂,过硫酸钠为引发剂,采用水溶液聚合法制备了椰糠粉/聚丙烯酸-丙烯酰胺复合吸水材料。较优的合成条件是:单体与椰壳粉质量比为8∶1,丙烯酸的中和度为70%,引发剂用量是单体质量的0.8%,交联剂N,N-亚甲基双丙烯酰胺用量是单体质量的0.2%,反应时间4h,温度50℃。对最佳条件下制备的吸水材料进行了FTIR和SEM表征及吸水性、保水性、重润胀性等测试,并且对该材料在去离子水和0.9%NaCl溶液中的吸水性进行对比。此外,用分子扩散方程及一级、二阶动力学模型对其吸水溶胀过程进行模拟研究。结果表明,该复合吸水材料在去离子水和盐溶液中的吸水倍率分别是273.54g/g和44.54g/g;吸水动力学表明水分扩散满足Fickian扩散,且一级动力学方程能描述润胀吸水过程;该材料重润胀3次后仍具有很好的吸水性。

A coconut husk powders/poly（acrylic acid-co-acryl amide）hybrid superabsorbent was prepared by means of solution polymerization reaction using coconut husk powders as matrix material,N,N-methylenebisacrylamide（MBA）as a cross-linker and sodium persulfate as an initiator.The optimum polymerizing conditions were as follows：mass ratio of monomer to cellulose was 8∶1,degree of neutralization was 70%,initiator content was 0.8%（referred to the monomers）,cross-linker content was 0.2%（referred to the monomers）,with reaction time and temperature of 4hand 50 ℃ respectively.FT-IR and SEM characterization,and water absorbency,retention,and reswelling properties of the absorbent prepared under optimum conditions were conducted.In addition,the water absorbencies of as-obtained composite superabsorbent for water and 0.9% NaCl solution were measured with results of about 273g/g and about 43g/g,respectively.The first-and second-order swelling kinetic models were used to simulate the kinetic swelling property of the polymers.The results showed that the pervasion of water into the hybrid superabsorbent obeyed Fickian diffusion mechanism,and the kinetic swelling processes coincided with Scott first-order swelling kinetic model.The polymer maintained excellent water retention property after reswelled for 3times.