Effects of addition of clay and alumina nanoparticles on flame-retardant, thermal, and mechanical properties of polyolefin elastomer/magnesium hydroxide composite

This study aims to develop extreme cold temperature resistance and non-halogenated flame retardant sheathing material for Arctic shipboard cables. A series of polyolefin elastomer (POE)/magnesium hydroxide (MHO)-nanosized clay (CL) and POE/MHO-nanosized alumina (AL) composites were prepared by melt-blending and their flame-retardant, thermal and mechanical properties were evaluated. The results reveal that the AL showed a synergistic effect in improving flame-retardant and tensile properties, oil resistance, and thermal stability of the POE/MHO. Notably, the tensile strength, elongation at break, and limit oxygen index of the POE/MHO composite with 1.2 phr AL increased by 54.9%, 39.5%, and 5.2%, respectively. Crucially, except for POE/MHO-CL1.2 phr, the glass transition temperature of all composites remained below −66 °C. Overall, 1.2 phr AL content is deemed optimal for the desired properties.