An eco-friendly non-isocyanate polyurethane treated by CO2 as flame retardant nanocomposite coating/ZrO2@SiO2

The utilization of renewable resources to provide a flame-retardant coating trend based on non-isocyanate polyurethane (NIPU) materials is inevitable. In this work, a series of advanced NIPU polymer was fabricated by the reaction of a cyclocarbonate and aromatic diamine. Sunflower oil cyclocarbonate was prepared by epoxidizing the oil using hydrogen peroxide in epoxidation reaction. The carbon dioxide was used for the cyclocarbonation process. The epoxidized product was subjected to a facile carbonized with carbon dioxide to yield ecofriendly cyclocarbonate. Zirconia @ silica (ZrO2@ SiO2) particles were formed by in situ method which binds zirconia nanoparticles with silica nanospheres. Aminolysis curing reaction was performed between the cyclocarbonate and 1,4-phenylendiamine to yield NIPU coating film for flame retardant applications. Various concentrations of ZrO2@SiO2 nanofillers were incorporated in NIPU matrix. Each product was analyzed and approved by using different investigation methods. The thermal stability and flammability properties were studied via thermal gravimetric analysis (TGA), limiting oxygen index (LOI). Mechanical performance and chemical resistance were evaluated as durability factors. High flammability resistance was shown where a high tolerance to direct fire contact was observed without ignition. Excellent mechanical properties and chemical stability for the prepared NIPU coatings were discussed in comparison by previous studies for NIPUs.