Novel Bismaleimide Porous Polymer Microsphere by Self-Stabilized Precipitation Polymerization and Its Application for Catalytic Microreactors

Herein, monodisperse and nanoporous poly(bismaleimide-co-divinylbenzene) microspheres (PBMs) are fabricated via one-pot self-stabilized precipitation polymerization of 2,2′-bis[4-(4-maleimidophenoxy)phenyl]propane and divinylbenzene in the absence of any dispersants and templates. The particle size, specific surface area, and pore structure of the PBMs could be effectively tailored by tuning the monomer feed ratio and solvent composition. Under optimum reaction conditions, uniform PBMs with a particle size of 1.37 μm were obtained, which exhibit a maximum Brunauer–Emmett–Teller (BET) surface area (556.25 m2/g) and pore volume (0.48 cm3/g). This novel fabrication method for PBMs has significant merits including a simple process free of additives and high efficiency. Furthermore, PBMs loaded with Pd nanoparticles (PBMs@Pd) were easily synthesized via in situ chemical reduction and used as a catalytic microreactor due to their abundant pore structure. As an efficient heterogeneous catalyst for the reduction of 4-nitrophenol (4-NP) by sodium borohydride (NaBH4), the as-prepared PBMs@Pd exhibited excellent catalytic activity with a high turnover frequency value (967.92 h–1) and excellent recyclability. This facile strategy opens up new horizons for the synthesis of porous microspheres with a well-controlled morphology and tunable pore structure, which have great application prospects in the fields of catalysis, adsorption, and energy storage.