03/24/2023
By Danielle Fretwell

The Francis College of Engineering, Department of Plastics Engineering, invites you to attend a master’s thesis defense by Olivia Ferki on “Reactive Extrusion of Post-Consumer Polypropylene and its Use as a Compatibilizing Agent for Immiscible Polymer Blends.”

Candidate Name: Olivia Ferki
Degree: Master’s
Defense Date: Tuesday, April, 4, 2023
Time: 12:30 to 2 p.m.
Location: Perry 215

Committee:

  • Advisor Margaret Sobkowicz Kline, Plastics Engineering, UML
  • Davide Masato, Plastics Engineering, UML
  • Akshay Kokil, Plastics Engineering, UML

Brief Abstract:

Polyolefins are ubiquitous in the plastics packaging and film sector due to their flexibility, thermal stability, low cost, and barrier properties. Alternative recycling methods are emerging that can provide high value secondary feedstocks from plastics packaging and films. Recycling polyolefin packaging via reactive extrusion for use as compatibilizers in immiscible polymer blends is a new technique that encourages the substitution of recycled waste streams for functionalized virgin polymers. Functionalized polyolefins containing reactive side groups are known to provide improved properties to blends of incompatible resins including processability, homogeneity, and mechanical properties. However, the compatibilized resin market is limited to virgin based grafting resins. In this work, we employ a melt grafting strategy to achieve reactive functionality, apply the method to post-consumer polypropylene (PP), and demonstrate its use as a compatibilizer in an immiscible polymer blend, poly(ethylene terephthalate) (PET) and PP. The post-consumer PP was functionalized through the addition of a peroxide catalyst and maleic anhydride during quad screw extrusion. The compatibilized blends are characterized using spectroscopy, thermal analysis techniques, and tensile testing to determine the grafted content and resulting processing behavior as well as mechanical behavior. The reactive extrusion process is compared with that for functionalizing virgin polypropylene, and the scale up and economics are discussed.