From the Waste Semicoke to Superabsorbent Composite: Synthesis, Characterization and Performance Evaluation

Oil shale semicoke (SC), which generated during the production of shale oil has attracted much attention in agriculture recently, as the composition of organic matter, clay mineral and else. In this study, a novel superabsorbent composite of poly(acrylic acid-co-acrylamide)/semicoke (P(AA-co-AM)/SC) was prepared by polymerization of the acrylic acid (AA) and acrylamide (AM) via a convenient one-step reaction as the presence of SC. The characterization of FTIR, SEM, XPS and TG indicated that the successful polymerization and the SC had participated into the construction of 3D polymeric network in superabsorbent. The performance testing results showed that the superabsorbent composites exhibited the excellent water absorbency, favorable water retention properties, fast swelling rate, and nice water reusability. And a 10% of SC amount could improve the water absorbency to 643.13 g/g and 79.82 g/g in distilled water and 0.9% NaCl solution, respectively. The potted culture experiments revealed that the increased water retaining capacity of soil and obvious growth promoting effect for crop. In a word, the novel superabsorbent composite could be as a potential water-saving product used in the agriculture, and the approach reported in this work also can be as a new pathway for high value using of SC via a sustainable chemical engineering process.