Thermally Reversible Polymeric Networks from Vegetable Oils.

Area of Science:

• Polymer Chemistry
• Materials Science
• Sustainable Chemistry

Background:

• Development of recyclable and reusable polymers is crucial for sustainable materials.
• Bio-based oils offer a renewable feedstock for polymer synthesis.
• Thermally reversible networks enable self-healing and reprocessing capabilities.

Purpose of the Study:

• To synthesize low cross-link density, thermally reversible networks from vegetable oils.
• To investigate the attachment of furan groups onto triglycerides from jatropha and sunflower oils.
• To evaluate the potential of these bio-based polymers as adhesives.

Main Methods:

• Epoxidation of jatropha and sunflower oils.
• Reaction of epoxidized oils with furfurylamine to introduce furan groups.
• Polymerization of furan-modified oils with aliphatic and aromatic bismaleimides.
• Characterization of chemical structure, thermal properties (T_g), and mechanical behavior during thermal cycling.

Main Results:

• Successfully synthesized furan-modified triglycerides from jatropha and sunflower oils.
• Jatropha oil modification retained triglyceride structure better than sunflower oil.
• Resulting polymers exhibited glass transition temperatures (T_g) between 3.6 and 19.8 °C.
• Evidence of Diels-Alder and retro-Diels-Alder reactions, indicating thermal reversibility.
• Reduced reversibility over cycles attributed to maleimide homopolymerization and adduct aromatization.
• Two polymers demonstrated adhesive properties without modification.

Conclusions:

• Low cross-link density thermally reversible networks can be synthesized from vegetable oils.
• The synthesized polymers exhibit potential for adhesive applications.
• Challenges in maintaining long-term reversibility were observed, suggesting areas for further research.