MOFs-based core-shell micro-nanostructure covering with curly RGO nanoflakes enabled fire-safe and mechanical-robust EP composites

Abstract

The extended usage of epoxy (EP) resin has confronted with the notorious issue of high fire hazard. Hence, a metal–organic frameworks (MOFs)-based core–shell micro-nanostructure covering with curly reduced graphene oxide nanoflakes (NRGO-ZIF@CoFe) is constructed and characterized via SEM, TEM, XPS, XRD, etc. Interfacial interaction between filler and matrix is estimated by microstructures analysis of fractured surfaces. Ulteriorly, the influences of NRGO-ZIF@CoFe on flame retardancy and mechanical performance of EP are investigated by cone test and tensile as well as flexural tests. When 2.0 wt% NRGO-ZIF@CoFe is loaded, the peak heat release rate, total heat release, peak smoke production rate, total smoke production are impaired by 42.8%, 23.5%, 41.0%, 39.2%. Meanwhile, the peak CO yield is depressed by 46.6%. Comparison with reported works demonstrates the advantage of NRGO-ZIF@CoFe in hindering heat and smoke productions. The evidences for inhibited releases of toxic volatiles (CO, NO, HCN) are offered via gases phase analysis. Stemming from the strong mechanical interlocking forces, the tensile and flexural strengths are promoted by 40.7% and 37.1%. Also, the elongation at break is elevated by 23.8%. In brief, this work may shed a light on the design of MOFs-based hierarchical architecture, further enabling fire-safe and mechanical-robust polymer composites.