Constructing High-T_g and Ultra-Strong Multifunctional Thermosets Enabled by Acid-Base Ion Pairs.

Area of Science:

• Materials Science
• Polymer Chemistry

Background:

• Thermosetting epoxy resins (TERs) are crucial in demanding industries like aerospace and electronics.
• Traditional TERs face a trade-off between high glass transition temperature (T_g)/mechanical strength and elasticity/reprocessability.

Purpose of the Study:

• To engineer novel TERs that overcome the conventional limitations of T_g, mechanical strength, elasticity, and reprocessability.
• To develop high-performance, recyclable epoxy thermosets through innovative molecular design.

Main Methods:

• Integration of high-energy-dissipation acid-base ion pairs (ABIPs) into densely crosslinked covalent adaptable networks.
• Development of a new class of TERs, named SEP_-COOH, utilizing this molecular engineering strategy.

Main Results:

• SEP_-COOH demonstrates a high T_g (> 245°C), excellent mechanical strength (77.9 ± 1.5 MPa), and superior impact toughness (8.2 MJ m^-2).
• Achieved ultrafast surface reprocessing and enhanced thermal conductivity in composites due to the internal catalytic effect of ABIPs.
• Performance comparable to commercial low-viscosity resins used in structural applications.

Conclusions:

• The developed SEP_-COOH resins offer an unprecedented combination of toughness, thermal stability, and reprocessability.
• This breakthrough in epoxy thermoset design provides a sustainable route to recyclable, high-performance polymers.