Semi-coke-enhanced eco-friendly superabsorbent composites for agricultural application

The superabsorbent polymers (SAP) possessed the favorable properties of absorbing and holding water, as well as the good degradability are urgently required for modern agriculture. And the grafting polymerization based on the natural polymers is an effective method for preparation of the SAP with degradability. In this work, a novel degradable SAP of CTS-g-PAA/SC was successful prepared via grafting the acrylic acid onto the chitosan (CTS) and introducing the oil shale semi-coke (SC) as inorganic component. The structure, morphology and thermal stability of the SAP were systemically studied by FTIR, SEM and TGA. Meanwhile, the water absorption capacities of SAP in different pH or various saline solutions as well as the reusability and the water retention capacity in soil were also investigated. The result suggested that the successful grafting polymerization and the SAP possessed the excellent water absorption capabilities, which were as high as 514.5 g/g in distilled water and 60.3 g/g in 0.9 wt% NaCl solution, respectively. More importantly, the cultivation experiments verified the SAP not only promoted the plants growth, but also could be degraded about 37.5% in the 70 days. Therefore, based on its excellent water retention, degradability and low cost, the SAP may have the great application potential in modern agriculture.

Automated summary

A novel degradable superabsorbent polymer (SAP) was successfully prepared through grafting polymerization, and its properties were systematically studied. The results showed that the SAP exhibited excellent water absorption capabilities and degraded significantly, suggesting its great potential in modern agriculture.