Environmentally Friendly, High-Performance Fire Retardant Made from Cellulose and Graphite.

Leandra P Santos,Fernando Galembeck,Douglas S Da Silva,Thais H Morari

doi:10.3390/polym13152400

Leandra P Santos, Fernando Galembeck + Show 2 more

Open Access

https://doi.org/10.3390/polym13152400

Copy DOI

Abstract

Many materials and additives perform well as fire retardants and suppressants, but there is an ever-growing list of unfulfilled demands requiring new developments. This work explores the outstanding dispersant and adhesive performances of cellulose to create a new effective fire-retardant: exfoliated and reassembled graphite (ERG). This is a new 2D polyfunctional material formed by drying aqueous dispersions of graphite and cellulose on wood, canvas, and other lignocellulosic materials, thus producing adherent layers that reduce the damage caused by a flame to the substrates. Visual observation, thermal images and surface temperature measurements reveal fast heat transfer away from the flamed spots, suppressing flare formation. Pinewood coated with ERG underwent standard flame resistance tests in an accredited laboratory, reaching the highest possible class for combustible substrates. The fire-retardant performance of ERG derives from its thermal stability in air and from its ability to transfer heat to the environment, by conduction and radiation. This new material may thus lead a new class of flame-retardant coatings based on a hitherto unexplored mechanism for fire retardation and showing several technical advantages: the precursor dispersions are water-based, the raw materials used are commodities, and the production process can be performed on commonly used equipment with minimal waste.

Highlights

We describe the fire-retardant properties of exfoliated and reassembled graphite (ERG) coatings, adding a new property to this polyfunctional material and showing how the dispersant cellulose contributes to build an effective fire barrier
The particles undergo extensive exfoliation that is evidenced by Representative micrographs are shown in Figure 2, where the two upper images are transmission electron microscopy from particles collected from dilute solutions
The combination of cellulose adhesion and dispersing properties is another demonstration of the versatility of this polymer due to its recently acknowledged amphiphile character

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Cellulose molecules are chemically simpler than most polysaccharides and other natural polymers. Celluloses obtained from different living species display remarkably diverse properties due to their hierarchical self-assembly [1,2]. Exploiting the polymer’s chemical modification and chirality is increasing the ever-growing list of applications of cellulosic materials rapidly [3,4,5,6,7]

Methods

Results

Discussion

Conclusion