The influence of well-dispersed mesoporous hydroxystannate ferrate anchored magnesium hydroxide hybrids on enhancing interfacial compatibility and fire safety of EVA/EPDM composites

Abstract

In this work, an innovative methodology for enhancing the fire safety of EVA/EPDM (EE) composites by employing an in-situ encapsulation technique to integrate magnesium hydroxide (MH) within the mesoporous hydroxystannate ferrate (mHSF) framework via ion-driven self-assembly. Comprehensive characterization involving X-ray diffraction, scanning electron microscopy, and transmission electron microscopy was employed to investigate the structure, elemental composition, and morphology of the resulting hybrids. In comparison to EE/MH composites, the MH@mHSF hybrids exhibited favorable dispersion within the EE matrix, demonstrating minimal aggregation. Upon incorporation of MH@mHSF hybrids, a significant reduction in peak heat release rate and total heat release (73.5 and 50%) compared with pristine EE, and an achievement in limiting oxygen index value of 32.5% from 19% for pristine EE was achieved. Notably, when contrasted with the findings of EE/MH/mHSF, the EE/MH@mHSF composite showcased superior tensile strength and enhanced fire safety properties. This improvement can be ascribed to the catalytic charring behavior and adsorption effects facilitated by well-dispersed MH@mHSF hybrids within the polymer matrix. Thermogravimetric analysis/infrared spectrometry (TG-IR) corroborated a substantial reduction in organic volatiles and the suppression of carbon monoxide emissions upon integration of MH@mHSF hybrids, underscoring the alleviation of fire hazards. The observed synergy of the catalytic and adsorption effects of mesoporous HSF, combined with the flame-retardant characteristics of MH, plays a pivotal role in the suppression of smoke generation.