Engineering of Flexible-Rigid Binary Complementary Network toward Mechanically Robust Elastomers Simultaneously Integrating Extreme Low-Temperature and High-Temperature Resistance

There is a significant need for elastomers that retain their elastic characteristics and mechanical robustness at temperatures ranging from extremely low to extremely high. However, low- and high-temperature resistances are mutually exclusive. Here, a mechanically robust elastomer that integrates low-temperature resistance and high-temperature resistance is fabricated using a multiblock polymer of polybutadiene (PB)/polyimide (PI). The elastomer exhibits an ultralow glass transition temperature of -82 degrees C and retains its elastic characteristics from -60 to 90 degrees C. The elastomer has a flexible-rigid binary complementary network, in which the PI segments with a highly conjugated structure and significant aromaticity aggregate to form phase-separated nanodomains to cross-link flexible PB segments. Serving as nanofillers, nanodomains strengthen the elastomer and significantly enhance its high-temperature resistance. Furthermore, the nanodomains prevent the crystallization of PB segments and thus ensure their high flexibility at low temperatures. The mechanical properties of the elastomer under cold, normal, and elevated temperatures exceed those of general-purpose rubbers and previously reported low-temperature elastomers. Moreover, the elastomer is highly stable in acidic and basic aqueous solutions. This elastomer holds particular promise as a tire tread compound because it provides excellent winter traction and ultralow rolling resistance.