Dynamically crosslinked-interpenetrating networks for sustainable 3D-printed elastomeric foams

Area of Science:

• Materials Science
• Polymer Chemistry
• Additive Manufacturing

Background:

• 3D-printed elastomeric foams offer design versatility but face foaming challenges due to high crosslinking in vat photopolymerization.
• Supercritical fluid foaming is an eco-friendly process hindered by material limitations.

Purpose of the Study:

• To develop a photocurable resin system for improved supercritical fluid foaming of 3D-printed elastomeric materials.
• To create a sustainable method for fabricating high-performance, recyclable hierarchically porous materials.

Main Methods:

• Incorporation of dynamic hindered urea bonds into a polyurethane acrylate matrix with amine-based curing agents.
• Integrated photocuring and supercritical fluid foaming to form a dynamically crosslinked-interpenetrating network.
• Characterization of mechanical properties, microcellular architecture, and recyclability.

Main Results:

• The novel resin system enabled enhanced foaming, producing uniform, crack-free microcellular elastomeric foam.
• The foam exhibited high tensile strength (5.5 MPa), elongation at break (510.8%), and excellent resilience.
• Recycled material retained impressive mechanical properties, with tensile strength of 8.9 MPa and elongation of 965.5% after reprocessing.

Conclusions:

• The dynamic crosslinking strategy overcomes limitations in supercritical fluid foaming for 3D-printed elastomers.
• This approach offers a sustainable pathway to high-performance, recyclable hierarchically porous materials with tunable properties.