Enhancing Stability of Reprocessed Acrylonitrile-Butadiene-Styrene (ABS) Polymers from Sorted WEEE Streams for...

Area of Science:

• Materials Science
• Polymer Chemistry
• Sustainable Engineering

Background:

• Mechanical recycling of styrenic polymers like acrylonitrile-butadiene-styrene (ABS) from waste electrical and electronic equipment (WEEE) is hindered by thermomechanical degradation during reprocessing.
• This degradation compromises the material's properties and limits its reuse in high-value applications.

Purpose of the Study:

• To systematically investigate the degradation behavior of ABS recovered from WEEE through multiple extrusion cycles.
• To evaluate the effectiveness of antioxidant stabilization in mitigating degradation and enhancing the recyclability of ABS.
• To demonstrate the potential of stabilized recycled ABS in additive manufacturing.

Main Methods:

• Multiple extrusion cycles were used to induce and study degradation in recycled ABS.
• Chemical structure, rheological, thermal, mechanical, and colorimetric analyses were performed to assess degradation.
• Antioxidant-stabilized ABS compounds were prepared and subjected to identical reprocessing.
• Filament extrusion for fused filament fabrication was used to demonstrate processability.

Main Results:

• Repeated processing led to increased melt flow, altered viscoelasticity, reduced molecular weight, deteriorated mechanical properties, and discoloration.
• Antioxidant addition effectively reduced chain scission, stabilized rheological properties, and minimized color changes.
• Optimized recycled ABS demonstrated good processability for additive manufacturing.

Conclusions:

• Antioxidant stabilization is crucial for enhancing the process stability and recyclability of ABS from WEEE.
• Stabilized recycled ABS can be utilized in higher-value applications, such as additive manufacturing, supporting a circular economy.
• This study provides a viable strategy for improving the sustainable use of recycled styrenic polymers.