Efficient and economical synthesis of flame retardant rigid polyurethane nanocomposite foam through phosphorus-based compounds and in-situ exfoliated microcrystal muscovite

Abstract

ABSTRACT A flame retardant rigid polyurethane foam (FR-RPUF) boasting good mechanical properties is developed by integrating phosphorus-based compounds (DBHP/DMMP) and organically modified microcrystal muscovite (OM-MCM). During foaming, OM-MCM undergoes in-situ exfoliation, yielding RPUF nanocomposites with heightened mechanical strength. The combined deployment of OM-MCM and DBHP/DMMP enables FR-RPUF to achieve an excellent flame retardancy (such as UL94 V-0 rating). This flame retardant effect stems from a bi-phase mechanism: trapping effect of phosphorus-containing radicals in the gas phase and enhanced charring of nanominerals in the condensed phase. Overall, this accessible method enhances flame resistance in RPUF using conventional processes and available materials.