Flame retardancy afforded by polyaniline deposited on wood

Abstract

Wood scantlings were coated with polyaniline (PANI) during the in situ polymerization of aniline with ammonium peroxydisulfate in an aqueous medium. The coating was made in hydrochloric or phosphoric acid solutions in both the absence and presence of stabilizers, poly(N-vinylpyrrolidone) or colloidal silica. The PANI-coated wood was placed in a flame or in a furnace operating at 400 or 6008C, and the decrease in the mass was determined. The wood coated with PANI was less reduced in its mass than uncoated samples and was converted to charcoal rather than to ashes. The deposition of related polymers, polypyrrole and poly(1,4-phenylenediamine), provided similar protection against heat exposure. Fourier transform infrared and Raman spectra of the residues after the burning of PANI-coated wood were compared. The soaking of wood in PANI colloids did not result in similar protection of wood against fire; the coating of the cellulose fibers with PANI during the polymerization was needed for the enhanced stability of wood at elevated temperatures. The concept of carbonization processes at the surface layer of PANI-coated cellulose fibers leading to the formation of carbonaceous microtubes is offered to explain the improved stability of wood against flame and heat exposure.

Nanodiamond-mediated crystallization in fibers of PANI nanocomposites produced by template-free polymerization: Conductive and thermal properties of the fibrillar networks

“…As widely reported in literature, a compact granular structure is the most typical morphology of PANI produced by the precipitation in strongly acid media [11]. Accordingly to this, a powder constituted by bright green micrometer-sized grains has been obtained in the case of the pure PANI polymer prepared by the chemical oxidization of the aniline monomer in the concentrated HCl aqueous solution ( Fig.…”

Structure and properties of conducting bacterial cellulose-polyaniline nanocomposites

“…Some of them involve the ''in situ'' polymerization of pyrrole (Py) or aniline (Ani) in the presence of cellulose pulp suspension (Johnston et al 2006;Kelly et al 2007;Qian et al 2010), pulp fibers and papers (Johnston et al 2005;Stejskal et al 2008;Goto 2011), wood or sawdust (Ansari and Pornahad 2010;Sapurina et al 2005;Stejskal et al 2007) microfibrillated cellulose (Nystrom et al 2010) or individual cellulose fibers extracted from Cladofora green algae (Mihranyan et al 2008). Also a chemical polymerization-induced adsorption process was employed for obtaining conducting polymers uniformly coated on cellulose fiber from commercial filter paper (Huang et al 2005).…”

Synthesis of poly(o -phenylenediamine) nanofiber with novel structure and properties

“…Now-a-days, the investigations on the aromatic diamine polymers become attractive over the well-known conjugated polymers like polyaniline, polypyrrole, polythiophene and their derivatives etc. [4] This is because of widely varying characteristics viz. variable conductivity, good electroactivity, colorful electrochromism, good optical properties, magnetic activity etc.…”