Fire- And Bio-Protective Sandwich Coatings for Wood with Nanodispersed Silica

Abstract

The possibility of creating sandwich fire- and bio-protective coatings by soft surface modification of wood based on phosphorus-containing compounds and nanodispersed silica has been investigated. Nitrilotrimethylphosphonic acid C3H12NO9P3, hereinafter NTP, was chosen as an organophosphorus modifier. Monoamonium phosphate NH4H2PO4 was chosen as a phosphorus-containing inorganic modifier. Polyacrylamide of the composition (CH2CHCONH2)n (magnoflok) was also used to create a coating on the surface of some samples. During laboratory tests, the fire-hazardous properties of the samples according to GOST 27484-87, their water absorption according to GOST 16483.20-72, mycological resistance according to GOST 9.048-89 were evaluated, and the marginal wetting angle of the surface of the samples was determined. The best characteristics of the studied ones were possessed by a sample coated with NTP, 40% + (Magnoflok + SiO2, 20%). This coating corresponds to the first class of fire-retardant efficiency according to GOST R 53292-2009, is mycological-resistant according to GOST 9.048-89, and also reduces the water absorption of wood according to GOST 16483.20-72 by 2 times. Also, this coating to some extent increases the hydrophobicity of the surface, for its greater increase it is advisable to apply an additional layer consisting of hydrophobizers on top of this coating.