Synthesis of decorated polyborosiloxane for enhancing the flame retardancy and mechanical property of epoxy resin

In this work, the decorated polyborosiloxane (MAPBS) with phosphorus-nitrogen components was first synthesized via a hydrolysis-condensation reaction and thus incorporated the MAPBS filler into epoxy resin (EP) to fabricate composites by a simple blending method. It could be found that the MAPBS with epoxy groups showed a good dispersion level in the EP matrix, endowing EP composites with superior flame retardancy and mechanical properties. Thanks to the combination of phosphorus-, nitrogen-, boron-, and silica-containing units in MAPBS filler, the addition of 6 wt% MAPBS made EP achieve significantly improved limiting oxygen index (25.2 ± 0.5%) and UL-94 rating (V1). Meanwhile, cone calorimeter test results revealed that the peak heat release rate (PHRR), total heat release (THR), and total smoke production (TSP) of the EP-MAPBS6 composite were reduced by 31%, 62%, and 67%, respectively, as compared to the pure EP. In addition, the MAPBS6 composite exhibited balanced tensile strength (105.1 MPa) and elongation at break (87.6%) among the prepared samples. The present work provides an effective strategy to fabricate EP composites with improved comprehensive performances.