凹凸棒黏土纯度对复合高吸水性树脂吸水性能的影响

Effect of the Purity of Attapulgite on Water Absorbency of Carboxymethylcellulose Sodium /Poly(acriylic acid)/Attapulgite Superabsorbent Composites

摘要:

将凹凸棒黏土分级处理后，以不同纯度的凹凸棒黏土为无机组分，以过硫酸铵为引发剂，N,N’-2-亚甲基双丙烯酰胺为交联剂，制备了羧甲基纤维素接枝丙烯酸/凹凸棒黏土复合高吸水性树脂，考察了复合高吸水性树脂的吸水倍率、吸水速率和在不同pH介质中的溶胀性能。红外光谱表明丙烯酸已接枝到羧甲基纤维素的骨架上，凹凸棒黏土参与了聚合反应。扫描电镜观察表明凹凸棒黏土在高吸水性树脂中有良好的分散性能，改善了基体表面的多孔结构。研究表明在相同添加量下，凹凸棒黏土中含有更多的Ca2+和Mg2+离子，有助于改善复合高吸水性树脂的综合性能。

Abstract:

In this paper, carboxymethylcellulose sodium/poly(acriylic acid)/attapulgite superabsorbent composites were prepared by aqueous solution polymerization using N,N’ –methylenebisacrylamide as crosslinker and ammonium persulfate as an initiator in the presence of different purity of attapulgite. The effect of the purity of attapulgite on water absorbency, water absorption rate and swelling properties in different pH medium were studied. FTIR spectra proved acriylic acid monomers were grafted onto the carboxymethylcellulose sodium backbone, and attapulgite participated in polymerization through its active silanol groups. FESEM observation showed that attapulgite fibrils led to a better dispersion in the polymeric matrix and formed a surface porous structure. More Ca2+ and Mg2+ in attapulgite are helpful to improve the swelling behaviors of the superabsorbent composites under the same content of attapulgite.