Biobased, Degradable, and Conjugated Poly(Azomethine)s.

Area of Science:

• Polymer Chemistry
• Materials Science
• Biobased Materials

Background:

• Carotenoids, biobased conjugated molecules, share structural similarities with conductive polymers like polyacetylene.
• Solubility is crucial for polymer processing, often enhanced by alkyl side chains in conjugated systems.
• Carotenoid-based polymers with tunable solubility and degradability remain underexplored.

Purpose of the Study:

• To synthesize and characterize novel carotenoid-based polymers with varying alkyl side chain lengths.
• To investigate the solubility and degradation properties of these biobased polymers.
• To explore carotenoids as building blocks for sustainable conjugated polymers.

Main Methods:

• Synthesis of carotenoid and p-phenylenediamine-based monomers via imine polycondensation.
• Quantitative solubility determination using ultraviolet-visible (UV-vis) absorption spectroscopy.
• Degradation studies employing UV-vis spectroscopy, 1H nuclear magnetic resonance (NMR), infrared (IR) spectroscopy, gel permeation chromatography (GPC), and high-resolution mass spectroscopy (HRMS).

Main Results:

• Carotenoid-based poly(azomethine)s with tunable solubility were successfully synthesized.
• Maximum solubility correlated with varying alkyl chain lengths.
• Polymers exhibited two degradation modes: accelerated degradation via acid hydrolysis and additional products from artificial sunlight exposure.

Conclusions:

• Carotenoid monomers are viable building blocks for creating biobased, degradable, and conjugated polymers.
• The developed polymer system demonstrates on-demand degradation capabilities.
• This research paves the way for sustainable alternatives in polymer science.