丙烯酸-丙烯酰胺原位插层共聚制备高吸水性蒙脱土纳米复合材料的研究

在钠基蒙脱土(MMT)悬浮液中，采用丙烯酸(AA)和丙烯酰胺(AM)两种单体进行原位插层共聚，得到高吸水性纳米复合材料。研究了引发剂和交联剂对材料吸水率的影响。X射线衍射(XRD)结果表明：复合材料中蒙脱土片层001面的层问距随mMMT／mM的减小而增大，当mMMT／mM≤1／3时，复合材料中的蒙脱土已完全剥离。DSC测试表明，在蒙脱土含量较低时，其玻璃化转变温度Tg随MMT含量的升高逐渐提高。吸水速率和保水能力测试结果表明，材料吸收去离子水能力达610g／gR，吸收盐水(wNaCl=0．009)能力达89g／gR。蒙脱土片层的引入。在一定程度上提高了材料的初期吸水速率和加压下的保水能力。

Preparation of Superabsorbent Montmorrilonite Nanocomposites by Method of in-situ Intercalation-Copolymerization with Acrylic Acid and Acrylamide

The superabsorbent nanocomposites were prepared by an in-site intercalation -copolymrization method with acrylic acid and acrylamide in montmorrilonite( MMT) suspension. The effects of initiator and cross-linker on their water absorption were studied. XRD results showedthat the layer spacing ( d001 ) are increasing with the monomer mass. Moreover, when the monomer mass is three times or more than that of MMT, no peak is shown in XRD spectrum to indicatie an exfoliated structure for the MMT. DSC shows that the glass transition temperature ( Tg ) of the nanocomposites increases with increasing the MMT content. Water absorption velocity and water retentivity under pressure tests indicated that the addition of nano-montmorrilonite (MMT) could improve the beginning absorption velocity and water retentivity for pure superabsorbent resin. The maximal water absorption of the composites achieved 610 g/gR for deionized water and 89 g/gR for 0.9% salt water.