Design of h-BN@boronate polymer core-shell nanoplates to simultaneously enhance the flame retardancy and mechanical properties of epoxy resin through the interficial regulation

In this report, we develop a simple and controllable coating strategy to decorate h-BN with a cyclotriphosphazene-containing boronate polymer (CPBP), thus forming [email protected] core-shell nanoplates with different shell thicknesses. By introducing [email protected] into epoxy resin (EP), we have found that the thermal stability, flame retardant and mechanical performances of the as formed nanocomposites greatly relies on the CPBP shell thickness. Also, our design effectively improve the compatibility between h-BN nanoplates and polymer matrix and regulate the corresponding interface. The nanocomposites show the highest limiting oxygen index (LOI) of 28.7% and reach V-0 rating in the vertical burning test at loading amount of 2.5 wt%. Also the heat and smoke releases of nanocomposites during burning are significantly reduced. The flexural strengths and modulus of the nanocomposites are at most 42.12% and 27.85% higher than that of pure EP. The glass transition temperature and dynamic mechanical property of the nanocomposites are both improved.