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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.

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The spinel‐type pigments of a general formula corresponding to AB2O4 containing as A the Mg2+ or Zn2+ ions and as B the Fe3+ or Al3+ ions or combinations of both the A and B were prepared and investigated with respect to their anticorrosive action as pigments in organic coatings. For the same purposes, comparative pigments, known for their efficiency as the metal‐corrosion inhibiting ingredients in similar formulations, were used. Further evaluation was carried out on the properties of condensed phosphates as anticorrosion pigments. The results obtained showed the high anticorrosion action of the spinel‐type pigments.