Study on the thermal decomposition kinetics and flammability performance of a flame-retardant leather

摘要

A flame-retardant leather (FR-leather) was prepared from blue wet leather treated with tetrakis hydroxymethyl phosphonium-melamine-pentaerythritol diphosphorate (THPM). An optimized genetic algorithm search method driven by Kissinger method was employed to estimate pyrolysis kinetic mechanism and the thermal stability of FR-leather. It is shown that the thermal decomposition of leather in nitrogen is a three-step kinetic scheme composed of the pyrolysis of triglyceride, multi-complexation collagen and single-complexation collagen, and the activation energies of the corresponding components of FR-leather are, respectively, 84.1, 172.6 and 253.6 kJ mol(-1). Accordingly, those of blank leather are 69.3, 161.3 and 105.4 kJ mol(-1). Meanwhile, cone calorimeter test demonstrates that when leather was treated with THPM, total heat release and total smoke production are decreased, respectively, 16.2 and 54.5%, and time to ignition increased from 20 s of blank leather to 26 s of FR-leather. The results of limit oxygen index value increased from 26.1% of blank leather to 32.9% of FR-leather, and the results of UL-94 vertical burning tests of FR-leather are significantly decreased, such as flame combustion time and length of carbonization decreased 88% and 72%, respectively. It is shown that the novel THPM material obviously improved the thermal stability and flame-retardant properties of leather fibers; at the same time, it has good smoke suppression effect and is an excellent flame retardant suitable for leather.