Flame‐Retardant Porous Polymers Containing Phosphoric Acid Moieties: A Facile Synthesis by Radical Polymerization of Multifunctional Methacryloyloxy Phosphate Inducing Phase Separation

ABSTRACT Porous polymers were successfully synthesized via conventional radical polymerization of multifunctional methacryloyloxy phosphate monomers, bis [2‐(methacryloyloxy)ethyl] phosphate (BMEP) and phosphoric acid 2‐hydroxyethyl methacrylate ester (PHME), in tetrahydrofuran (THF) through polymerization‐induced phase separation. Polymerizations of BMEP in various alcohols such as 1‐propanol, 1‐butanol, and n ‐hexanol at appropriate monomer concentrations also yielded porous networks. The resulting polymers exhibited monolithic morphologies composed of interconnected spherical particles with diameters of 1–2 μm. These porous monoliths were mechanically robust, showing no fracture under compression up to 50 N, and demonstrated excellent thermal stability, beginning to decompose around 280°C under both argon and dry air atmospheres while leaving 40–50 wt% residues at 500°C. The presence of phosphate groups within the polymer backbone effectively imparted flame retardancy to the materials.