Multimaterial Digital Light Processing Three-Dimensional Printing of Materials with Different Relaxation Kinetics

Area of Science:

• Polymer Science
• Materials Science
• Chemical Engineering

Background:

• Covalent adaptable networks (CANs) are dynamic polymer networks with tunable properties.
• Dynamic exchange reactions enable malleability, weldability, and recyclability in CANs.
• Kinetics of exchange reactions are influenced by dynamic link concentration and diffusion.

Purpose of the Study:

• Investigate the exchange dynamics in photocurable thiol-ene CANs.
• Quantify the contributions of Arrhenius behavior and Rouse diffusion to stress relaxation.
• Explore the potential of these materials as temperature-time sensors.

Main Methods:

• Studied thiol-thioester exchange mechanism in thiol-ene CANs.
• Utilized dual-vat multimaterial DLP 3D printing to create diverse materials.
• Evaluated creep performance and stress relaxation kinetics.

Main Results:

• Demonstrated tunable stress relaxation kinetics by varying dynamic link concentration.
• Identified the interplay between Arrhenius-like behavior and diffusion-controlled processes.
• Successfully fabricated multimaterial samples with distinct mechanical responses.

Conclusions:

• Thiol-ene CANs offer tunable mechanical properties through controlled dynamic exchange.
• Understanding the balance between kinetic and diffusion factors is crucial for material design.
• Multimaterial CANs can function as effective thermal-time sensors via thermal imprinting.