Multifunctional Lignin-Silver Nanoparticles for Accelerating Polymerization and Cross-Linking of Sodium Polyacrylate

The development of advanced additives for polyacrylic acid-based superabsorbent polymers is of great significance for the improvement of the water retaining and reuse capacities and the reduction of the energy consumption in the production. In this work, multifunctional lignin-silver nanoparticles (LANPs) were fabricated via a simple in situ reduction/nanoprecipitation method. The LANPs with lots of dynamically stable semi-quinone radicals were used for initiation and cross-link of sodium polyacrylate (SPA). The LANPs/SPA can be fabricated at room temperature by triggering of free radicals. The water absorption capacity of LANPs/SPA can reach 325.42 g/g and retain approximately 58.94% of water after 2 h at 45 °C. In addition, it can maintain at about 239.20 g/g even after the seventh reswelling. This approach not only can greatly reduce the production costs and improve the water absorption of SPA but also develop the lignin valorization.