N-Alkylated dinitrones from isosorbide as cross-linkers for unsaturated bio-based polyesters

Area of Science:

• Polymer Chemistry
• Organic Synthesis
• Materials Science

Background:

• Isosorbide-derived monomers offer a renewable platform for polymer synthesis.
• 1,3-dipolar cycloaddition is a versatile reaction for polymer modification and network formation.

Purpose of the Study:

• To synthesize novel dinitrones from isosorbide.
• To cross-link a bio-based unsaturated polyester using these dinitrones via 1,3-dipolar cycloaddition.
• To investigate the impact of this cross-linking on the material's mechanical properties.

Main Methods:

• Esterification of isosorbide with acryloyl chloride and crotonic acid.
• Reaction of isosorbide derivatives with benzaldehyde oxime using Zn(II) iodide and BF3·OEt2 catalysts to form dinitrones.
• Cross-linking of poly(isosorbide itaconite-co-succinate) with the synthesized dinitrones.
• Rheological measurements to evaluate mechanical property changes.

Main Results:

• Successful synthesis of isosorbide diacrylate, isosorbide dicrotonate, and N-alkylated dinitrones.
• Significant changes in mechanical properties of the bio-based polyester after cross-linking, confirmed by rheological analysis.
• Model system studies characterized the 1,3-dipolar cycloaddition reaction.

Conclusions:

• The 1,3-dipolar cycloaddition effectively cross-links bio-based unsaturated polyesters.
• This cross-linking method induces substantial alterations in mechanical properties.
• The study provides a pathway for developing novel, sustainable polymeric materials with tunable characteristics.