Valorization of Unused, Expired Surgical Masks in Polymer-Modified Bitumens Using Maleic Anhydride as a...

Area of Science:

• Materials Science
• Sustainable Engineering
• Polymer Chemistry

Background:

• Polymer-modified bitumen (PMB) enhances asphalt performance.
• Surgical masks contain valuable polypropylene (PP) that is often discarded.
• Recycling PP from masks presents a sustainable material recovery opportunity.

Purpose of the Study:

• To evaluate recovered polypropylene (PP) from surgical masks as a substitute for virgin PP in PMB.
• To functionalize mask-derived PP to improve its compatibility with bitumen.
• To assess the performance of PMB formulations containing recycled PP.

Main Methods:

• Polypropylene was recovered from unused surgical masks.
• Maleic anhydride (MAH) and a compatibilizer (AUS) were used for PP functionalization.
• Five PMB formulations were prepared and tested for viscosity, penetration, and softening point.

Main Results:

• ATR/FT-IR confirmed no thermo-oxidative degradation during mixing.
• MAH-functionalized mask-derived PP (PMB_MMAH) showed the best performance.
• Compared to base bitumen, PMB_MMAH exhibited a ~10-15 °C higher softening point, ~20-30% increased viscosity, and up to 25% reduced penetration.

Conclusions:

• Mask-derived PP is a viable and sustainable substitute for virgin PP in PMB.
• Functionalization enhances the performance of recycled PP in bituminous binders.
• The study demonstrates potential for improved technical performance and material circularity.