Covalent Adaptable Polymethacrylate Networks by Hydrazide Crosslinking Via Isosorbide Levulinate Side Groups

Area of Science:

• Polymer Chemistry
• Materials Science
• Biocatalysis

Background:

• Reversible crosslinking enhances polymer properties and enables chemical recycling.
• Acylhydrazone bonds, formed via ketone-dihydrazide reactions, provide network reversibility.
• Biobased monomers offer sustainable alternatives to petroleum-based polymers.

Purpose of the Study:

• To synthesize a novel isosorbide-based monomer with a pendant levulinoyl group.
• To create and characterize dynamic covalent polymethacrylate networks with tunable properties.
• To demonstrate the recyclability and reusability of these biobased thermosets.

Main Methods:

• Two-step biocatalytic synthesis of isosorbide monomethacrylate with a levulinoyl group.
• Radical copolymerization of the isosorbide monomer with methyl methacrylate.
• Post-polymerization crosslinking using dihydrazides and acidic cleavage for de-crosslinking.

Main Results:

• Successfully synthesized and polymerized novel biobased monomers.
• Crosslinked networks showed enhanced thermal properties (Tg up to 170 °C, thermal stability up to 286 °C).
• Demonstrated efficient cleavage of acylhydrazone bonds under acidic conditions and successful polymer re-crosslinking.

Conclusions:

• Novel levulinic isosorbide-based dynamic polymethacrylate networks exhibit excellent recyclability and reusability.
• These materials hold significant potential for developing sustainable, biobased thermoset polymers.
• The dynamic covalent chemistry approach facilitates a circular economy for polymer materials.