Thermostability and flame retardance of green functional two-component waterborne polyurethane coatings with nanoparticles

A new kind of green and functional two-component flame-retardant waterborne polyurethane and its coating were synthesized through adding polyurethane polyol dispersions, hydrophilic nanoTiO2 and hydrophilic curing agent. The properties and analysis were characterized via FTIR, laser particle analyzer, rheometer, TEM, TGA, TGA-FTIR, LOI tester, SEM, UV-vis spectrum, water and solvent resistance. The results showed the tensile strength counld reach 22.3 MPa. And the nanoTiO2 delayed speed of thermal decomposition to improve thermostability of two-component waterborne polyurethane. Larger quantities of hydrophilic nanoTiO2 did not produce a larger unbroken carbon yield surface or thicker carbon layers, but effectively produced a condensed phase flame-retardant effect with OP550 during burning. Besides, LOI and UL-94 also reached over 29.4% and V-0 respectively. The UV and visible light shielding noticeably increased with the adding nanoTiO2. The 0.5% content of nanoTiO2 had the optimal properties in green and functional two-component waterborne polyurethane coatings.