Polyurethane/acrylic hybrid dispersions containing phosphorus reactive flame retardants as transparent coatings for wood

Phosphorus modified polyurethane/acrylic hybrid dispersions were prepared for flame retardant transparent wood coatings. The polymerisation was carried out in three steps. In the first one, polyurethane synthesised using an acrylic monomer as solvent. second step involved water addition that promoted phase inversion and lastly, part polymerised. phosphorous compounds covalently linked to a phosphorylated polyol phosphate. Polymerisation monitored by FTIR NMR molar mass of hybrids measured AF4 SEC. effects phosphorus fire-retardant properties analysed thermogravimetry pyrolysis combustion flow calorimetry. introduction did not produce significant changes process but cross-linking coated samples maintained transparency good with presented slight reduction Peak Heat Release Rate cone calorimeter. action fire effective it gave rise CO CO2 peaks.