Flame Retardation of Polyamide 6 by Electro-Sprayed Phosphorus–Copper Complex Supported by Layered Silicate

Abstract The primary objective of this study was to demonstrate the effect of a phosphorus–copper complex on the flammability of polyamide 6 (PA6) materials, including organoclay-reinforced nanocomposites. The secondary objective was to compare the effectiveness of the deposition methods of the three-layer copper complex. Our previous work successfully revealed the effectiveness of reducing the flammability of polyamide composites by depositing phosphorus and copper compounds using a Layer-by-Layer technique. In the current work, we turned our attention to modifying the PA6 surface by electro-spray (ES) using the same flame retardants as before, and we investigated the effectiveness of the resulting surface protection against high temperatures during combustion. Surface roughness analysis revealed that the use of the ES method favors the formation of surface unevenness. The UL-94 test results showed that composite materials having 5-15 triple layers were among the best flammability classes compared to the others. Both types of materials tested also showed a tendency to reduce the heat release rate (HRR) by increasing the degree of surface coverage when using the electro-spray technique. Remarkably, deposition of 15 triple layers on the surface of the nanocomposite reduced the maximum HRR point by 20%. Graphical abstract