28.03.2025

3D printing technology enables the precise fabrication of plastic components with minimal material waste. However, there is a lack of high-performance polymers that are also recyclable. Researchers at the Georgia Institute of Technology have developed a new class of polymers, polythioenones, which are mechanically and chemically recyclable and outperform conventional polyolefins in mechanical properties.

Innovative Materials for 3D Printing

3D printing, particularly Fused Filament Fabrication (FFF), offers significant advantages in manufacturing. However, sustainability challenges arise due to the difficulty of recycling many commonly used polymers. “A chemically recyclable polymer that can be broken down into its monomers and re-polymerized would be a major step toward a circular economy,” the research team states.

Diagram: chemical synthesis and recyclability of polythioenones, alongside a 3D-printed sample demonstrating the material’s practical application in additive manufacturing; Copyright: Wiley-VCH

Polythioenones, a newly developed class of recyclable polymers, demonstrate excellent mechanical properties and can be efficiently depolymerized for reuse in additive manufacturing. Copyright: Wiley-VCH

The Development of Polythioenones

The team led by Will R. Gutekunst and H. Jerry Qi developed a novel family of monomers: cyclic thioenones (CTE). These contain carbon, sulfur, and carbonyl groups, allowing them to polymerize into polythioenones (PCTE). What makes them unique is the reversible polymerization process, enabling efficient depolymerization and reuse.

A standout material in this polymer class is PCTE-Ph, which exhibits high thermal stability and excellent mechanical properties. "PCTE-Ph combines stability with sustainability and is highly suitable for additive manufacturing," explains the research team.

Mechanical and Chemical Recyclability

PCTE-Ph enables two recycling options:

Mechanical Recycling: The material can be remelted and reprocessed while retaining its thermal and mechanical properties.
Chemical Recycling: Through a catalytic reaction, PCTE-Ph can be broken down into its original monomers with a 90% yield, which can be used for new polymerization cycles.

Advantages Over Conventional Polyolefins

Polythioenones offer several advantages over established polyolefins like polyethylene and polypropylene:

Improved mechanical strength
High thermal stability
Efficient recyclability
Reduced dependence on fossil resources

These properties make PCTE-Ph a promising alternative for sustainable 3D printing and other plastic applications.

Sustainable Materials for the Future

The introduction of polythioenones could mark a significant step toward more sustainable 3D printing. With their excellent mechanical performance and full recyclability, these polymers contribute to the advancement of the circular economy in the plastics industry.