Flame retardant and smoke suppression properties of 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide derivative/zinc molybdate sepiolite modified acrylate emulsion

Acrylate emulsion is widely used in various industrial fields and is an important polymer emulsion. However, the high flammability limits its application. Besides, acrylate emulsion generally releases a large amount of smoke during combustion. To improve the fire resistance and smoke suppression properties of acrylate emulsions, methyl methacrylate-butyl acrylate copolymer P(MMA-BA)/DOPO-based polymerizable monomer (HEPO)/zinc molybdate sepiolite (Mo-Sep) composite emulsion was prepared by emulsion polymerization, and the effect of Mo-Sep content on the flame-retardant performance, thermal stability, and smoke suppression performance of the composite emulsion was studied. Through microcalorimeter and smoke density meter tests, it was found that the heat release rate (HRR) of the composite emulsion, added with 30% HEPO/3% Mo-Sep, was reduced by 63.3%, and the peak heat release rate (PHRR) was reduced by 72.1%. The total heat release (THR) is reduced by 49.0%, while the peak-specific optical density is reduced by 48.0%. It shows that the composite emulsion has excellent flame-retardant and smoke suppression properties compared to pure MAA-BA emulsion. In addition, scanning electron microscope (SEM) images show that the addition of Mo-Sep increases the density of carbon residue. This composite emulsion may have potential application scenarios in the field of flame-retardant coatings.