Synthesis and Characterization of Cardanol-Based Non-Isocyanate Polyurethane

Area of Science:

• Polymer Chemistry
• Green Chemistry
• Materials Science

Background:

• Traditional polyurethanes (PUs) often rely on hazardous isocyanates.
• There is a growing demand for sustainable and bio-based alternatives in polymer production.
• Cardanol, a byproduct of cashew nut shell processing, offers a renewable resource for chemical synthesis.

Purpose of the Study:

• To develop a novel, environmentally friendly synthesis route for non-isocyanate polyurethane (NIPU) using cardanol.
• To characterize the intermediate products and the final NIPU material.
• To evaluate the potential of cardanol-based NIPU as a sustainable material.

Main Methods:

• Cardanol and formaldehyde were reacted to form a cardanol formaldehyde oligomer, catalyzed by citric acid.
• The oligomer underwent epoxidation using m-chloroperbenzoic acid to yield an epoxide compound.
• The epoxide was reacted with carbon dioxide (CO2) to form a cyclic carbonate, which was then reacted with an amine to produce NIPU.
• Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), and thermogravimetric analysis (TGA) were employed for characterization.

Main Results:

• Successful synthesis of four intermediate compounds and the final cardanol-based NIPU.
• Characterization data confirmed the structure and purity of the synthesized materials.
• The study demonstrated the feasibility of using cardanol as a renewable feedstock for NIPU production.

Conclusions:

• A viable and sustainable synthetic pathway for producing bio-based NIPU from cardanol has been established.
• The synthesized NIPU shows promise as an eco-friendly alternative to conventional polyurethanes.
• This research contributes valuable insights into the synthesis and characterization of renewable polyurethanes.