Synthesis and characterization of waterborne and phosphorus containing flame-retardant polyurethane coatings

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2002
Çelebi, Funda
In this study, phosphorus containing flame retardant water-dispersed polyurethane paints were produced by incorporating different amounts of phosphorus compound onto the polyurethane main chain. The novel flame retardant compound was synthesized in three steps. In the first step, monobenzalpentaerythritol was produced from benzaldehyde and pentaerythritol. In the second step, phosphorylation of monobenzal pentaerythritol was performed. Final step includes the formation of phosphorus phenyl dihydroxyl from the hydrolyzation of the resulting product in acetic acid solution. IllWater-dispersed polyurethane paint was produced using polyester polyol, isophorone diisocyanate and dimethylol propionic acid (DMPA) as a hydrophilic monomer. To improve the physical and thermal properties of the waterborne polyurethanes, 5% (w/w) polyisocyanate and melamine were used as crosslinking agents. By changing the feed ratio of polyester and phosphorus compound, the flame retardant water-dispersed polyurethane paints with different phosphorus contents were obtained. All the synthesized products were characterized by H-NMR, P-NMR and IR spectroscopies, and the thermal stabilities of the polymers were evaluated by their DSC and TGA thermograms. The effects of increasing phosphorus content on the physical and thermal properties of polyurethane paints were also examined. The addition of phosphorus phenyl dihydroxyl to the main chain increased the hardness but slightly decreased the gloss values of the polyurethane paints. All the samples showed superior impact resistance, and flexibility. Increasing phosphorus content increased the char yield and the maximum fire retardancy was reached at 1.5%P content with the limiting oxygen index value of 29. Further addition of phosphorus decreased the flame resistance of polyurethane paints.
Citation Formats
F. Çelebi, “Synthesis and characterization of waterborne and phosphorus containing flame-retardant polyurethane coatings,” Middle East Technical University, 2002.