Selective recovery of polypropylene (and polyethylene) from mixed plastic wastes


Project ID: D2021-43


Polypropylene (PP) is a thermoplastic polymer used in packaging materials, consumer goods, automotive components, and medical devices. It is difficult to recover PP from mixed plastic waste streams; PP has a similar density to polyethylene (PE) and cannot be selectively separated from PE via the sink-float methods that are often used to separate these polyolefins from other plastics. Although the market for recycled PP and PE is large, only ~1% of PP and PE produced globally are recycled due to the lack of suitable recycling technologies.

 Invention Description

Researchers at the University of Toledo have developed a chemical process that uses green solvents to selectively solubilize PP. At the right conditions, the PP dissolves in the solvents but not PE or other plastics. Dissolved PP is subsequently reprecipitated from the solvent and recovered. When applied to plastic “floats”, this method allows separation and recovery of both PP and PE.


  • Selective recovery of PP
  • Separation of PP and PE from mixed plastic waste streams 
  • Production of recycled PP and PE products


  • Sustainable alternative to current methods
  • Environmentally sustainable, low-cost and reusable solvent
  • Recycled product has a virgin-like high quality

IP Status:                        Patent Pending

Patent Information:
For Information, Contact:
Katherine Pollard
Licensing Associate
The University of Toledo
Parikshit Sarda
Balakrishna Maddi
Joseph Lawrence
Sridhar Viamajala