Soda-anthraquinone pulping and cationization of Posidonia oceanica

Abstract

Every year, millions of tonnes of dead biomass from algae and seagrasses are collected on the Mediterranean coasts. Posidonia oceanica is one of the most abundant species. In this work, leaves and rhizomes from this plant were pulped, alkalized, and cationized to make a value-added product. The main effects of five separate pulping variables, namely temperature, time, NaOH concentration, anthraquinone, and liquid-to-solid ratio were studied. The total procedure to produce cationic fibers took only 3 h (approximately), which made it a feasible process. A pseudo-second-order rate equation was used to fit the results of chemical modification via incorporation of quaternary ammonium ions. Characterization involved X-ray diffraction, scanning electron microscopy, and elemental analysis. The authors found that mild conditions were enough to achieve good results, reaching degrees of substitution of 0.20 for leaves and 0.12 for rhizomes.