Hydrolyzable Bio-Based Bisphenols Enabled by the Tishchenko Reaction for Polyurethane Vitrimers with Closed-Loop...

Area of Science:

• Materials Science
• Polymer Chemistry
• Green Chemistry

Background:

• Conventional polyurethanes (PUs) rely on petroleum, posing environmental concerns due to limited recyclability.
• Developing sustainable alternatives to petroleum-based plastics like bisphenol A (BPA) is crucial.

Purpose of the Study:

• To create a fully bio-based polyurethane vitrimer system.
• To develop a simplified, atom-efficient synthesis for bio-based bisphenols.
• To achieve tunable properties, recyclability, and degradability in PUs.

Main Methods:

• A dual-function SmI2-mediated strategy integrating Tishchenko coupling and phenol deprotection in one step.
• Synthesis of bio-based bisphenols with hydrolyzable ester bonds.
• Characterization of Covalent Adaptable Network (CAN) PU properties.

Main Results:

• A simplified, 100% atom-utilizing synthesis for bio-based bisphenols.
• Complete degradation of the PU system within approximately 3 days.
• Tunable dissociation temperatures (70-120 °C) for reprocessability and recyclability.
• Enhanced thermomechanical performance: tensile strength up to 33 MPa, elongation >400%, toughness 30 MJ/m³.

Conclusions:

• Pioneered a scalable, fully bio-based PU vitrimer platform.
• Demonstrated tunable performance, recyclability, and sustainable degradability.
• Offers a compelling green alternative to traditional thermosets and thermoplastics.