Biorenewable Polyelectrolyte Nanocoating for Flame-Retardant Cotton-Based Paper

Abstract

Cotton-based raw paper, made of 100% cellulose, is used to make humidity-sensing, cottonid for bio-architecture applications. Despite its renewability and excellent mechanical properties, it is inherently flammable. In an effort to reduce its flammability, thin films of fully renewable and environmentally benign polyelectrolytes, chitosan (CH) and phytic acid (PA), were deposited on raw paper via layer-by-layer (LbL) assembly. Only four bilayers (BL) of the CH/PA coating are required to achieve self-extinguishing behavior, with a 69% reduction in peak heat release rate measured by microscale combustion calorimetry. These results demonstrate that this renewable intumescent LbL-assembled film provides an effective flame-retardant treatment for these environmentally friendly, climate-adaptive construction materials and could potentially be used to protect many cellulosic materials.

Lignin beyond the status quo: recent and emerging composite applications

“…Chemical crosslinking was found to be an important influence on the firm and uniform internal structure of the films that enhanced the UV barrier property and prevented self-aggregation that was observed in the physical films. 93 Rodriguez-Melendez et al 94 synthesized lignin-based 'green' and intumescent flame retardant by making a blend of lignin, casein, and polyacrylonitrile (PAN) followed by linking the blend with different wt.% of phytic acid. The multicomponent FR samples were tested by limiting oxygen index (LOI), UL-94, and cone calorimetry.…”

“…Rodriguez-Melendez et al 94 synthesized lignin-based ‘green’ and intumescent flame retardant by making a blend of lignin, casein, and polyacrylonitrile (PAN) followed by linking the blend with different wt.% of phytic acid. The multicomponent FR samples were tested by limiting oxygen index (LOI), UL-94, and cone calorimetry.…”