Preparation and properties of an eco-friendly superabsorbent based on flax yarn waste for sanitary napkin applications

Recently, cellulose-based superabsorbent has attracted attention as a promising material in many fields because of its rich sources and outstanding properties of biodegradability and biocompatibility. This study examines the potential application of a novel flax yarn waste-g-poly(acrylic acid-co-acrylamide) (FYW/PAA) superabsorbent in the absorbent core layer of sanitary napkins. Acrylic acid (AA) and acrylamide (AM) were grafted onto the pretreated flax yarn waste (PFYW) by free-radical graft copolymerization in homogeneous aqueous solution. The synthesis conditions of the FYW/PAA superabsorbent and its application performance for sanitary napkin were investigated. The results showed that, under the optimal synthesis conditions, the water absorbency of the prepared FYW/PAA reached 787.6 g/g in deionized water, 109.5 g/g in 0.9 wt% NaCl solution and 206.5 g/g in artificial blood solution. The composited absorbent core layer containing the FYW/PAA achieved the similar artificial blood solution absorbency of 192.6 g/g and retention of 83.9 wt% to those of the marketed sanitary napkin products. Meanwhile, a weight residue of 53.6 wt% was attained for the FYW/PAA after being buried in soil for 90 d.