Effect of Melamine and its Salts on Combustion and Thermal Decomposition of Polyamide 6

摘要

Melamine and its salts added to polyamide 6 (PA-6, nylon 6) improve its fire retardancy as measured by oxygen index and UL94 tests. The mechanism of the fire-retardant action of the additives was studied using thermogravimetry, kinetics of thermal decomposition and characterization of solid residues and evolved high-boiling products. It was found that melamine, melamine oxalate, melamine phthalate and melamine cyanurate facilitate thermal decomposi- tion of PA-6 with increasing evolution of oligomeric chain fragments instead of caprolactam, which is the principal product evolved from the nonfire-retarded PA-6.