Ternary Siloxane Copolymers Based Tough Elastomer under Ultralow Temperatures Condition

The preparation of tough elastomer materials for use in ultralow temperature environments (<−100 °C) has always been a challenge in materials science. Despite polydiethylsiloxane being recognized as a promising material, its crystallization at low temperatures (−75 °C) significantly limits its application under ultralow temperature conditions. In this study, we used simulation-assisted design to optimize a ternary random copolymerized silicone with a glass transition temperature of −149 °C, which is a potential candidate material to withstand ultralow temperature environments. We experimentally synthesized diethyl–dimethyl–diphenyl ternary random copolysiloxanes based on the insights obtained from molecular dynamics simulations. Differential scanning calorimetry experiments confirmed that the glass transition temperature of the ternary random copolymerized silicone was as low as −140 °C, and the crystallization was effectively suppressed. Low-temperature tensile experiments further showed that the elongation at break exceeded 200% at −110 °C, the toughness reached 27 MJ/m 3, and the fracture energy reached 590 kJ/m 2 . At the ultralow temperature of −130 °C, the fracture energy of the material reached 650 kJ/m 2, and the tear strength reached 52 kN/m, demonstrating exceptional tear resistance. This study provides a feasible solution for the preparation and engineering applications of elastomer materials resistant to ultralow temperatures.