Polymerization of hydroxylated graphitic carbon nitride as an efficient flame retardant for epoxy resins  

Abstract

Graphitic carbon nitride (GCN) has been recognized as a potential flame retardant (FR) due to its high thermal stability and nitrogen richness. Previous work has been limited to hybridization without involving covalent modification. Here, we developed a facile covalent modification approach to polycondensation that can chelate with metal ions (PCNOH-CuCo) from GCN. Structural and mechanical property characterization confirmed the ability of PCNOH-CuCo to be uniformly dispersed in the epoxy resin (EP). Fire tests showed excellent fire resistance of EP with 10 wt% PCNOH-CuCo (EP/10PCNOH-CuCo), including a limiting oxygen index of EP/10PCNOH-CuCo up to 31.5%, and the reduction in the peak heat release rate, total heat release, peak smoke production, total smoke production peak CO production, and peak CO2 production of 47.9%, 37.5%, 20%, 44.5%, 30.9%, and 42.5%, respectively. This work provides a solution for the fabrication of GCN-based FRs and their derived metal-doped FRs