Functionalizing mesoporous silica with a nano metal–organic phosphonate towards mechanical‐robust, thermal‐resistant, and fire‐safety epoxy resin

Abstract

AbstractEpoxy resin (EP) has featured many industrial and practical applications, but was plagued by its inherent flammability. Herein, a hybrid flame retardant (mSiO2@TETP) was fabricated by in‐situ immobilizing tin ethylenediamine tetramethylene phosphonate (TETP) on the mesoporous silica (mSiO2) surface, and was used to prepare mechanical‐robust, flame‐retardant, and thermal‐resistant EP composites. It is found that the introduction of only 1.0 wt% mSiO2@TETP into EP leads to a 20.5%, 19.7%, and 12.8% incremental tensile modulus, tensile strength, and impact strength, respectively. The EP composite with 5.0 wt% mSiO2@TETP (EP/mSiO2@TETP‐5) succeeds to the UL‐94 V‐0 grade, with a limiting oxygen index value of 29.0%. And the peak heat release rate, total heat release, peak smoke production rate, total smoke release, and peak CO production rate of EP/mSiO2@TETP‐5 decrease by 54.0%, 52.1%, 53.9%, 51.1%, and 55.7%, respectively in contrast with the values of pure EP. Moreover, the introduction of mSiO2@TETP results in an improvement in both the charring capacity and the initial thermal resistance (an increment in the glass transition temperature) of EP.