Nanonetwork Thermosets from Templated Polymerization for Enhanced Energy Dissipation

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Thermosets like phenolic and epoxy resins are intrinsically brittle.
• Developing methods to enhance their mechanical properties, particularly energy dissipation, is crucial for broader applications.

Purpose of the Study:

• To fabricate mechanical metamaterials with enhanced energy dissipation.
• To utilize self-assembled block copolymers as templates for creating nanonetwork thermosets.
• To investigate the influence of gyroid and diamond nanostructures on thermoset properties.

Main Methods:

• Templated polymerization of phenolic and epoxy resins using polystyrene-polydimethylsiloxane block copolymers.
• Creation of gyroid (tripod) and diamond (tetrapod) network structures.
• Nanoindentation testing to measure energy dissipation.
• Finite element analysis to understand structural contributions.

Main Results:

• Fabricated nanonetwork thermosets with gyroid and diamond structures.
• Phenolic resins: Gyroid (0.23 nJ) and diamond (0.33 nJ) showed enhanced energy dissipation.
• Epoxy resins: Gyroid (0.57 nJ) and diamond (0.78 nJ) demonstrated significantly higher energy dissipation.
• Enhanced properties attributed to isotropic periodicity and increased strut density in diamond networks.

Conclusions:

• Facile fabrication of mechanical metamaterials with improved energy dissipation is achievable.
• Templated polymerization with block copolymers offers a route to engineer thermoset properties.
• The gyroid and diamond nanonetwork architectures effectively enhance energy absorption in brittle thermosets.