Properties of magnesium hydroxide modified by silicone rubber and its flame retardant EVA composites

Due to the low flame retardant efficiency of Magnesium Hydroxide (MH), a significant interaction exists between flame retardants and Ethylene Vinyl Acetate Copolymer (EVA) composites regarding their flame retardant and mechanical properties during flame retardant modification. This trade-off effect restricts the widespread application of such composites in engineering. In this paper, silicone rubber (SR) was employed for the modification of MH coating (SR-MH) and further utilized for enhancing the flame retardancy of EVA (EVA/SR-MH). The oxygen index, mechanical properties, and volume resistivity of the EVA/SR-MH composite were systematically investigated. The results indicate that the water contact angle of SR-MH reaches 119.5°, demonstrating a significant enhancement in surface polarity. When the flame retardant content is 40wt.%, the Limiting Oxygen Index (LOI) of the EVA/SR-MH composite increases by 85%, the peak heat release rate (pHRR) decreases by 29%, the tensile strength improves by 103%, the elongation at break increases by 41%, and the volume resistivity rises by 362%. These findings confirm that the comprehensive properties of the composite are markedly enhanced.