Effects of adding organo-clays for acrylic-based intumescent coating on fire-retardancy of painted thin plywood

Intumescent material with commercial resin, such as acrylic copolymer resin, has been demonstrated to be extremely effective in improving the fire performance of wooden materials used for indoor furnishing. This study investigates the enhancement of painted thin red lauan (Parashorea spp.) plywood by using intumescent coating with organo-clays added with different types of Cloisite 30B, Cloisite 10A and Cloisite 15A and different amounts of organo-clays (1, 3, 5 and 10%). These intumescent formulations significantly enhanced the fire retardancy of painted plywood, exhibiting lower peak heat release rates (PHRR) and extending the time to reach PHRR, as compared with plywood panels coated with intumescent coating with absence of organo-clay. Therefore, the amount of organo-clays added in intumescent is important. In additional, 3% of Cloisite 30B and 5% of Cloisite 10A further enhanced fire retardancy. The FT-IR, 27Al and 31P NMR analyses demonstrated that adding organo-clay extended the survival duration of the phosphor-carbonaceous chars structure.

► Acrylic emulsion resin added with different types of organo-clays can enhance the fire performance by extending the time to reach PHRR.
► The mechanism of fire performance with addition of Cloisite 10A (5%) and 30B (3%) were shown better than those with a high content of organo-clays (i.e., 10%).
► Unit of AlOx can react with phosphorous and forms Al[OP]6.
► The longer phosphorcarbonaceous structures enhance the better fire performance.