Analysis of kinetics of thermal decomposition of melamine blended with phosphorous ionic liquid by green approach

As a common halogen-free flame retardant, melamine is vastly employed in flame-retardant fields of various polymer materials. To preferably optimize the flame retardancy of melamine, a phosphorous ionic liquid of 1-butyl-3-methylimidazolium dibutyl phosphate ([Bmim][DBP]) was introduced as a synergist. In this study, a novel synergistic flame retardant was prepared through an easy operated physical mixing. Then, pyrolysis behavior of melamine and its compounds were measured using thermogravimetric analysis. The apparent activation energy and pre-exponential factor were evaluated using Kissinger–Akahira–Sunose method and Flynn–Wall–Ozawa method, and the most probable kinetic function was also determined using double extrapolation method. Results showed that the addition of [Bmim][DBP], in general, improved thermal stability and residual capacity of melamine. It meant that melamine blended with [Bmim][DBP] possessed the synergistic flame-retarding potential from the preliminary analysis. Significantly, accurate and reliable thermal decomposition kinetic models of melamine and its compounds were established and the kinetic compensation effects were also discussed. More relevant combustion tests would be performed in the following study.