Novel cellulose nanowhiskers-based polyurethane foam for rapid and persistent removal of methylene blue from its aqueous solutions

To realize the concept of e2 i.e., economical and environmentally–friendly materials for the environmental protection, the biomass or the polysaccharides can be used as starting materials, as polyols, to develop new bio-based polyurethane foam (PUF), a cost-effective and versatile polymer material with wide range of applications, which has been conventionally obtained from the reaction of polyol with polyisocyanate via urethane linkages. In the present study, new PUF was synthesized from cellulose nanowhiskers prepared by acidic hydrolysis of cellulose extracted from pine needles, and diphenylmethane diisocyanate. The synthesized PUF was characterized using various techniques and applied for the rapid and continuous removal of water effluents using methylene blue (MB) dye as model pollutant from its aqueous solutions. Almost complete MB removal was observed within 20 min at 55 °C with a very high maximum retention capacity of 554.8 mg/g and reusability for numerous repeat cycles.