Monolithic nanoporous polymers bearing POSS moiety as efficient flame retardant and thermal insulation materials

Abstract

The creation of porous materials with both good thermal insulation and flame retardancy is of great importance for construction of energy-saving coatings in many applications. Herein, we report the facile fabrication of octasilsesquioxane (POSS)-based monolithic nanoporous polymers (named as PDVB-POSS) by solvothermal method using octavinyl-POSS as monomer and divinylbenzene (DVB) as crosslinker followed by freeze drying. The as-prepared PDVB-POSS show abundant porosity with mesopore sizes ranging from 8 nm to 13 nm, which results in a high thermal insulation with a low thermal conductivity of 0.024 W m−1 k−1 in air. The PDVB-POSS also possesses excellent flame retardancy with a peak heat released rate (pHRR) of as low as 144 W g−1. Torch burn test implies that the PDVB-POSS shows self-extinguishing behaviors without generation of any melt dripping, further reflecting an excellent flame retardancy. Taking advantages of simple fabrication process, easily to be scaled-up, excellent thermal insulation and flame retardancy, such POSS-based monolithic porous polymers may have great potential as energy-saving coatings for real applications.