Ternary Synergistic Flame-Retardant Coatings

In flame-retardant coatings, the mass ratio of flame-retardant to waterborne acrylic coating was set at 3:7. The waterborne acrylic coating without the addition of flame-retardant, referred to as the non-flame-retardant coating (A), was designated as the first control group. Within the waterborne acrylic coating, a certain amount of sodium silicate flame retardant was added without the use of urea or melamine modifiers to prepare the coating, referred to as the sodium silicate flame-retardant coating (AS). This was designated as the second control group. For the sodium silicate flame-retardant coating, coatings were prepared by adding urea and melamine modifiers. This was referred to as the sodium silicate/urea/melamine ternary synergistic flame-retardant coating, abbreviated as the ternary synergistic flame-retardant coating (ASMU). The ternary synergistic flame-retardant agent is prepared by mixing sodium silicate flame retardant, urea modifier, and melamine modifier in a certain ratio. The mass percentage of melamine was set at 7%, and when the mass percentages of urea were 3.5%, 7%, 10.5%, and 14%, the corresponding ternary synergistic flame-retardant coatings were labeled as ASM₇U_3.5, ASM₇U₇, ASM₇U_10.5, and ASM₇U₁₄, respectively. During the preparation of the ternary synergistic flame-retardant agent, waterborne acrylic coatings, sodium silicate, melamine, and urea were separately weighed according to the aforementioned ratios and placed into a beaker. The beaker containing the waterborne acrylic coatings was then placed into a constant temperature oil bath at 40 °C. Sodium silicate was added under stirring conditions and stirred for 10 min. Subsequently, melamine and urea were added separately and stirred for 30 min. After the coating was uniformly mixed, the sodium silicate/urea/melamine ternary synergistic flame-retardant coating was obtained.