The inherent renewability and biodegradability make lignocellulosic nanomaterials a promising green replacement for synthetic polymers. Compared to purely cellulose-based materials that are more commonly investigated, lignocellulosic nanofibrils (LNF) have drawn increasing attention as they feature greater feedstock utilization and reduced by-product production. To obtain LNF with improved fire resistance for building and construction applications, a reactive deep eutectic solvent (DES) is proposed in this study to produce LNF from chemi-thermomechanical pulp, a cost-effective wood industrial product, and simultaneously endow it with fire-retarding properties. This DES system consists of sulfamic acid and urea, two commodity chemicals at a 1:2 molar ratio. The results showed that, a reaction time of 7h is desirable to sufficiently fibrillate the pulp into LNF with high surface charge density; highly porous aerogel can be produced from the LNF via freeze-drying and give a reduced thermal diffusivity compared to the one directly made from pulp; the sulfate ammonium groups present at LNF release non-flammable gasses, serving as barrier to repel oxygen and giving the aerogel enhanced fire resistance. These create a great chance of converting cost-effective wood industrial commodity into functionalized LNF for fire-retarding thermal insulating materials in sustainable building and construction.

Functionalized lignocellulosic nanofibrils for fire-retarding thermal insulating materials

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.