Electrostatic assembly of metal organic frameworks nanocubes on electrochemically exfoliated graphene nanoflakes: Superior role in flame retardance

The extensive usage of epoxy resin (EP) is facing the head-scratching challenge of high fire hazard. As such, the electrostatic assembly of metal organic frameworks (MOFs) nanocubes on electrochemically exfoliated graphene nanoflakes is performed to acquire the hybrid of PG@UIO. The corresponding role and behavior in flame retardance are explored in detail. By adding 2.0 wt% PG@UIO, the reductions in peak heat release rate, total heat release, peak smoke production rate, peak CO yield, peak CO₂ yield reach 49.2 %, 44.3 %, 56.1 %, 57.7 % and 51.3 %. The in-situ volatiles analysis points out the reductions of 35.1 %, 29.4 %, 50.8 %, 32.5 % in the maximal intensities of aromatic compounds, ethers, CO and HCN. The mechanical interlocking area between PG@UIO nanostructures and EP molecular chains contributes to the enhanced mechanical performances. Specifically, by adding 2.0 wt% PG@UIO, the flexural strength is increased by 50.3 %. This work enables a new paradigm for fabricating fire-safe polymer composites with the judicious design of MOFs based flame retardant.