Effect of Cellulose-Based Bioplastics on Current LDPE Recycling

Area of Science:

• Materials Science
• Polymer Recycling
• Sustainable Plastics

Background:

• Bioplastics are increasingly found in municipal solid waste, often mixed with traditional polymers like low-density polyethylene (LDPE).
• Understanding the impact of bioplastic contamination on conventional plastic recycling is crucial for effective waste management.

Purpose of the Study:

• To evaluate the effect of cellulose acetate plasticized with triacetin (CAT) on the mechanical recycling of LDPE.
• To determine if CAT contamination affects LDPE's chemical, thermal, rheological, and mechanical properties during recycling.

Main Methods:

• Preparation of LDPE-CAT blends with varying CAT content (0-10% by weight) via melt extrusion.
• Analysis using scanning electron microscopy, Fourier-transform infrared spectroscopy, thermal analysis (TGA, DSC), rheological measurements, and tensile testing.

Main Results:

• CAT presence did not significantly alter LDPE's chemical, thermal, or rheological properties.
• No significant LDPE degradation was observed under typical processing conditions with CAT addition.
• CAT negatively impacted LDPE processability and mechanical behavior, reducing the quality of the recycled material.

Conclusions:

• Cellulose-based bioplastics like CAT should not be included in LDPE recycling streams.
• A dedicated sorting stream for bioplastics is recommended to maintain the quality of recycled LDPE.