A New Continuous Flow Microwave Radiation Process Design for Non-Isocyanate Polyurethane (NIPU).

Area of Science:

• Polymer Chemistry
• Green Chemistry
• Materials Science

Background:

• Non-isocyanate Polyurethane (NIPU) synthesis typically involves thermal-ring-opening reactions of bis-cyclic carbonate (BCC) compounds with polyamines.
• BCC can be derived from epoxidized compounds and captured carbon dioxide, aligning with sustainable chemical practices.
• Microwave radiation offers a significantly faster laboratory-scale alternative to conventional heating for NIPU synthesis, exceeding conventional methods by over 1000 times.

Purpose of the Study:

• To design and evaluate a continuous, recirculating microwave radiation system for scaling up NIPU synthesis.
• To assess the energy efficiency and scalability of the novel microwave-assisted NIPU production process.
• To demonstrate the viability of a green and energy-saving method for industrial NIPU production.

Main Methods:

• Development of a continuous flow tube reactor integrated with a recirculating microwave radiation system.
• Synthesis of NIPU using bis-cyclic carbonate (BCC) and polyamines under microwave irradiation.
• Comparison of energy consumption (Turn Over Energy - TOE) between laboratory-scale batch and the new continuous microwave systems.

Main Results:

• The continuous microwave system demonstrated a substantial increase in reaction scale (up to 300 times) compared to lab-scale batch reactors.
• Energy efficiency significantly improved, with Turn Over Energy (TOE) decreasing from 24.38 kJ/g in batch to 8.89 kJ/g in the continuous system.
• The process proved to be over 1000 times faster than conventional heating methods for NIPU synthesis.

Conclusions:

• The newly designed continuous and recirculating microwave radiation system provides a reliable, energy-saving, and convenient method for scaling up NIPU synthesis.
• This microwave-assisted approach represents a significant advancement towards greener and more efficient industrial production of Non-isocyanate Polyurethane.
• The enhanced energy efficiency and scalability confirm the potential of this method as a sustainable alternative in polymer manufacturing.