Thermal decomposition characteristics of amino modified ZIF-67 synergistic modified epoxy resin flame retardant material

The study on the pyrolysis kinetics of epoxy resin (EP) materials serves as a bridge connecting the performance of basic materials and terminal industrial applications. In this work, amino functionalized zeolite imidazole ester skeleton material (NH₂-ZIF-67), melamine polyphosphate (MPP) and phosphorus containing low molecular polyphenylene oxide (MPPO) were employed to modify EP to prepare EP flame retardant materials. The pyrolysis kinetics of EP flame-retardant materials was analyzed by combining multiple iso-conversional model-free methods and using the constructed Coats-Redfern-master plot method. The results showed that with the incorporation of flame retardant, both the activation energy (E_a) and pre-exponential factor (A) of the EP flame retardant materials were lower than those of pure EP. The addition of 1wt% NH₂-ZIF-67 reduced the E_a of flame retardant materials to 48.78±2.37 kJ/mol, and the pyrolysis behavior of materials was more prone to occur. This was because MPP and NH₂-ZIF-67 materials in EP flame retardant materials had catalytic charring effect, and multi-component materials cooperated with each other in the pyrolysis process, which led to the acceleration of pyrolysis reaction. Common mechanism functions were analyzed according to Coats-Redfern and master plot method. The experimental curve and standard curve were the most consistent with F2 and F3 mechanism models. The pyrolysis behavior of EP flame retardant materials could be quantitatively described by random nucleation reaction.