Influence of Stabilization Additive on Rheological, Thermal and Mechanical Properties of Recycled Polypropylene

Area of Science:

• Polymer Science
• Materials Science
• Sustainable Materials

Background:

• Plastic waste reduction necessitates effective recycling techniques.
• Multiple recycling cycles degrade polymers, limiting the utility of recycled plastics.
• Polypropylene (PP) degradation affects its mechanical and thermal properties.

Purpose of the Study:

• To investigate the degradation of polypropylene (PP) through multiple recycling steps.
• To evaluate the efficacy of a stabilizing additive in enhancing recycled PP performance.
• To characterize the effects of recycling and additive incorporation on PP properties.

Main Methods:

• Spectroscopic analysis to identify degradation products.
• Rheological measurements to assess melt flow behavior.
• Optical and mechanical testing to evaluate material properties.
• Mechanical recycling and additive incorporation.

Main Results:

• Polypropylene undergoes chain scission and oxidation after 20 mechanical recycling steps.
• A small amount of stabilizing additive significantly improved recycled PP properties up to the 20th cycle.
• The additive enhanced rheological properties, surface characteristics, and mechanical performance.
• The additive acted as a hardener and crosslinked polymer chains, improving material integrity.

Conclusions:

• Stabilizing additives are crucial for mitigating degradation in recycled polypropylene.
• Additive incorporation extends the usability of recycled PP for plastic product manufacturing.
• This approach offers a viable strategy for improving the sustainability of polymer recycling.