Frontal Polymerization of Superabsorbent Nanocomposites Based on Montmorillonite and Polyacrylic Acid with Enhanced Soil Properties

摘要

Polyacrylic acid/montmorillonite(MMT)/carboxymethylcellulose (CMC) superabsorbent nanocomposites were prepared by frontal polymerization (FP), an economic method characterized by low-energy consumption and short-reaction time. They were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and scanning electron microscopy. The effects of reaction parameters on the front propagation and the water absorbency of the nanocomposites were investigated. Furthermore, the effects of the obtained products on soil water holding capacity and soil water stable macro-aggregates were studied. Compared with the control soil, soil mixed with the nanocomposites showed a significant increase (by 52.4%) in field water holding capacity. The incorporation small amounts of MMT effectively promoted the formation of soil water stable macro-aggregates, which increased by 76% as the addition of the MMT increased to 4 wt %. The samples obtained by FP showed much better performance in the formation of soil water stable macro-aggregates, salt resistance, and thermal stability than those obtained by conventional batch polymerization.