Sustainable valorization of waste polystyrene and PVC blends for high-performance applications

Area of Science:

• Materials Science
• Polymer Chemistry
• Waste Management

Background:

• Solid plastic waste disposal presents a significant global challenge, particularly for developing nations.
• Recycling waste plastics like polystyrene foam (WPS) and polyethylene terephthalate (PET) is crucial for sustainability.
• Developing novel materials from recycled plastics requires effective modification strategies.

Purpose of the Study:

• To chemically and mechanically recycle waste polystyrene foam and polyethylene terephthalate.
• To investigate the effects of recycled additives on the properties of waste plastic blends.
• To compare the performance of recycled additives with conventional plasticizers.

Main Methods:

• Chemical recycling of waste PET via glycolysis to produce glycolyzed product (GPET) and unsaturated polyester.
• Mechanical recycling of WPS using hot blending.
• Incorporation of Polyvinyl chloride (PVC), GPET, and polyester as additives into WPS/PVC blends.
• Evaluation of rheological, mechanical, electrical, thermal, and flame-retardant properties.

Main Results:

• Polyester significantly enhanced melt flow rate, flame retardancy, and reduced combustion energy.
• GPET improved tensile strength and elongation at break.
• Additives increased permittivity and conductivity; polyester showed the strongest dielectric response.
• SEM analysis indicated improved dispersion and compatibility in blends with GPET and polyester.

Conclusions:

• Recycled PET derivatives (GPET and polyester) act as effective multifunctional additives for waste polystyrene.
• The developed blends exhibit enhanced mechanical, thermal stability, and flame retardancy.
• These materials show potential for applications in electrical insulation, construction, and automotive components.