Molecular Pathways for Polymer Degradation during Conventional Processing, Additive Manufacturing, and Mechanical...

Area of Science:

• Polymer Science and Engineering
• Materials Science
• Chemical Engineering

Background:

• Polymer processing significantly impacts material properties and end-of-life recyclability.
• Degradation mechanisms during processing affect both performance and circularity.
• Conventional and additive manufacturing (AM) present unique challenges for polymer stability.

Purpose of the Study:

• To comprehensively review polymer degradation mechanisms during processing.
• To connect experimental characterization with modeling tools for degradation analysis.
• To provide guidelines for controlling polymer degradation at the molecular level.

Main Methods:

• Discussion of thermal, thermo-mechanical, thermal-oxidative, and hydrolysis degradation pathways.
• Analysis of degradation in extrusion-based manufacturing, mechanical recycling, and AM.
• Overview of experimental characterization techniques and their integration with modeling.

Main Results:

• Identified key degradation mechanisms across various polymer types (polyesters, styrene-based, polyolefins) and processing methods.
• Demonstrated the link between characterization methods and predictive modeling.
• Case studies highlight degradation behavior in specific polymers and AM applications.

Conclusions:

• Effective control of polymer degradation during processing is achievable through molecular-level understanding.
• Integrated experimental and modeling approaches are crucial for managing degradation.
• Guidelines are provided to enhance material performance and promote circularity.