Conversion of Contaminated Post-Consumer Polyethylene Terephthalate into a Thermoset Alkyd Coating Using Biosourced...

Area of Science:

• Materials Science
• Polymer Chemistry
• Sustainable Chemistry

Background:

• Developing sustainable coatings is crucial for reducing environmental impact.
• Recycling postconsumer waste polyethylene terephthalate (wPET) presents challenges for high-value applications.
• Thermoset alkyd coatings require specific polymer functionalities for performance.

Purpose of the Study:

• To develop a novel recycling strategy for wPET to synthesize high-performance thermoset alkyd coatings.
• To create a sustainable fatty acid-functional polyester from wPET.
• To overcome physical drying challenges in alkyd coating formulations.

Main Methods:

• A single-stage "depolymerization-repolymerization" process was employed to utilize wPET waste.
• The recycled polyester was copolymerized with glycerol and tall oil fatty acid.
• A convergent polymer formulation strategy was developed and combined with commercial alkyd driers.

Main Results:

• The process achieved 95% efficiency in exploiting the wPET waste stream.
• A sustainable fatty acid-functional polyester suitable for alkyd coatings was successfully synthesized.
• The resulting thermoset alkyd coating demonstrated suitability for industrial applications.

Conclusions:

• A high-performance thermoset alkyd coating can be synthesized from contaminated wPET.
• The developed "depolymerization-repolymerization" method offers an efficient recycling pathway.
• This approach provides a sustainable alternative for industrial coating applications.