From Formica® to FormiCAN: One-Pot Synthesis of Melamine-based Covalent Adaptable Network Endowed With High...

Area of Science:

• Polymer Chemistry
• Materials Science
• Sustainable Materials

Background:

• Melamine-based resins are widely used in laminates and composites.
• Traditional thermosets, including melamine resins, are non-reprocessable and persistent.
• Covalent adaptable networks (CANs) offer a promising alternative for reprocessable thermosets.

Purpose of the Study:

• To develop a melamine-based covalent adaptable network (CAN) with reprocessable and degradable characteristics.
• To investigate the synthesis, properties, and performance of this novel melamine-based CAN.

Main Methods:

• One-pot, solvent-free microwave-assisted synthesis of a melamine-based CAN with N,O-acetal exchangeable units.
• Characterization of thermo-mechanical properties (glass transition temperature, Young's modulus).
• Evaluation of hydrolytic stability, on-demand degradability, stress relaxation, creep, and reprocessability.

Main Results:

• The synthesized melamine-based CAN exhibits a glass transition temperature of 90 °C and Young's modulus up to 1 GPa.
• The material demonstrates high hydrolytic stability at room temperature but on-demand degradability under acidic conditions at elevated temperatures.
• The CAN shows rapid stress relaxation (30 s at 210 °C), low creep (0.6% at 150 °C), and is easily reprocessable (1.5 h at 170 °C) with no property degradation after three cycles.

Conclusions:

• A novel, reprocessable, and degradable melamine-based CAN has been successfully synthesized.
• This material offers a sustainable alternative to conventional thermosets, combining desirable mechanical properties with end-of-life options.
• The developed CAN shows significant potential for applications in laminates and composites requiring enhanced environmental performance.