The properties of flame retardant and heat conduction polyamide 66 based on melamine cyanurate/aluminum diethylphosphinate/graphene

Abstract

In this present paper, melamine cyanurate (MCA)/aluminum diethylphosphinate (AlPi) were used as composite flame retardants, and with addition of graphene (Gr) served as thermal conductive filler for preparing flame-retardant and thermal conductive polyamide 66 (PA66). The effects of Gr on flame retardancy, as well as the thermal conductivity on the combustion behavior of PA66 under the heat environment were investigated. The results demonstrated that Gr could effectively inhibit phosphorus-containing radicals from AlPi into gaseous phase and improve its impact on the condensed phase. Additionally, as a physical carbon source, two-dimensional sheets of Gr provide excellent barrier shielding effects and increase the residue, thus significantly retarding the melt drops during the combustion process. The results showed that the specimens with 12 wt% composite flame retardants and 3.5 wt% Gr, passed UL-94 V-0 rating (1.6 mm of thickness) and the total heat release (THR) were decreased by 22% according to micro-scale combustion calorimetry (MCC). Additionally, the improved thermal conductivity due to the addition of Gr, effectively enhances the thermal heat dissipation rate and decreases the risk of self-ignition caused by local heat accumulation.