"Dissolve-on-Demand" 3D Printed Materials: Polymerizable Eutectics for Generating High Modulus, Thermoresponsive and...

Area of Science:

• Polymer Chemistry
• Materials Science
• Photochemistry

Background:

• Solvent-free polymerization methods are desirable for sustainable material synthesis.
• High modulus polymers are crucial for advanced applications like 3D printing.
• Photopolymerization offers rapid curing and spatial control.

Purpose of the Study:

• To demonstrate solvent-free photopolymerization of vinyl monomers using polymerizable eutectic (PE) mixtures.
• To explore the potential of PE systems for creating high modulus materials for 3D printing and photoswitchable applications.
• To investigate the influence of PE formulation on material properties and processing.

Main Methods:

• Preparation of PE mixtures by heating and stirring N-isopropylacrylamide (NIPAM), acrylamide (AAm), and 2-hydroxyethyl methacrylate (HEMA).
• Characterization of structural and thermal properties using NMR spectroscopy, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA).
• Evaluation of UV photocuring kinetics via in situ photo-DSC and photorheology, and application in stereolithography (SLA) 3D printing.

Main Results:

• PE mixtures exhibit rapid UV photocuring kinetics.
• Resulting materials display storage moduli significantly higher than conventionally cured copolymers.
• Successful 3D printing of PE resins was achieved without crosslinkers due to inherent hydrogen-bonding networks.
• Incorporation of photoswitchable monomers and on-demand dissolvability were demonstrated.

Conclusions:

• Solvent-free photopolymerization of PE mixtures is an effective route to high modulus materials.
• PE systems offer a versatile platform for advanced applications including 3D printing and photoswitchable materials.
• The hydrogen-bonding network in PE systems facilitates crosslinker-free 3D printing and tunable material properties.