Simple and efficient approach for recycling of fine acrylic-based superabsorbent waste

Abstract

Recycling fine particles (smaller than 150 µm) of acrylic-based superabsorbent polymer is of a great importance due to environmental and economic issues. In this paper, fines or dust is agglomerated by soaking in treatment solution containing acetone, water and cross-linker and subsequently curing at 160 °C for 2 h. Bisphenol A diglycidyl ether resin (BADGE), ethylene glycol diglycidyl ether (EGDGE) and polyethylene glycol diglycidyl ether (PEGDGE) have been employed as crosslinking agents. The considered effective parameters includes: cross-linker type and concentration in treatment solution and acetone to water ratio. Swelling capacity in saline and deionized water, absorbency under load (AUL), storage modulus, recovery proportion (percentage of particles above 100-mesh screen) and optical microscope images were utilized to investigate accurately. All the cross-linkers could raise the particle size in 70 and 50 % acetone content by variation of maximum recovery percentages between 70 and 93. The best condition was found for BADGE cross-linker in 70 and 50 % acetone content with appropriate swollen gel strength and absorbencies. Besides both dry and wet agglomeration were firmly integrated. Therefore, crosslinking agglomerated particles is a promising way to recycle fine SAP waste on account of its simplicity and efficiency. Recycling fine particles of acrylic-based superabsorbent polymer waste is of a great importance due to environmental and economic issues. Crosslinking agglomerated particles as a promising approach has been considered to reuse the fine SAP. Three different crosslinking agents were employed to compare their productivity. Swelling capacity in saline and deionized water, absorbency under load (AUL), storage modulus, recovery proportion and optical microscope images were utilized to investigate accurately.