Simultaneous enhancement of fire retardancy and ceramifiable properties in polyolefin-based composites using melamine cyanurate and layered tri-metallic hydroxide

• This study synthesized layered tri-metal hydroxide (MgAlBi-LTH) with dual flame-retardant and fluxing functionalities through one-pot hydrothermal synthesis . • The composite demonstrated exceptional performance under extreme thermal stress, enduring 90-minute butane torch exposure while preserving electrical functionality. • This work establishes a robust foundation for subsequent development of high-performance fire-safe polymer composites . Ceramifiable cables develop a robust ceramic layer under high-temperature conditions, preventing internal conductor meltdown while maintaining electrical transmission integrity during fire events. Nevertheless, these materials often fail to satisfy applicable cable industry standards owing to inadequate ceramification characteristics or flame retardancy. In this work, a two-dimensional layered tri-metal hydroxide was synthesized through a simple hydrothermal method and combined with melamine cyanurate to create a synergistic flame retardant system. This formulation was integrated into an ethylene vinyl acetate (EVA)-based composite formulated with hollow glass microspheres, glass powder, and montmorillonite as ceramic-forming fillers (CF), yielding a lightweight, flame-retardant ceramifiable composite. Fire resistance evaluations revealed that the material formed a dense protective ceramic layer, enabling uninterrupted circuit functionality following 90-minute butane flame exposure. The ceramic layer demonstrated 15.2 MPa flexural strength, significantly exceeding the 10 MPa threshold required for splash resistance. The composite exhibits a limiting oxygen index of 24.7 % and achieves a UL-94 V-0 rating. Relative to pure EVA, peak heat release rate, total heat release, and total smoke production were reduced by 85.7 %, 28.4 %, and 87.1 %, respectively. This research establishes an enhanced foundation for developing cable materials with dual flame-retardant and ceramifiable functionalities, thereby expanding potential applications of ceramifiable cable systems.