09/06/2022
By Paulette Brooks

The Francis College of Engineering, Department of Plastics Engineering, invites you to attend a doctoral dissertation proposal defense by Shawn Martey on “Reactive Processing and Melt Compounding of Plastic Wastes by Incorporating Catalysts and Nanoparticles.”

Candidate Name: Shawn Martey
Defense Date: Wednesday, Sept. 14, 2022
Time: 10 a.m. to noon
Location: Perry 215. Those interested in attending should contact shawn_martey@student.uml.edu and committee advisor gracewanting_chen@uml.edu at least 24 hours prior to the defense to request access to the meeting.

Committee Advisors:

  • Margaret Sobkowicz-Kline, Professor, Plastics Engineering, University of Massachusetts Lowell
  • Wan-Ting (Grace) Chen, Assistant Professor, Plastics Engineering, University of Massachusetts Lowell

Committee Members:

  • Carol Barry, Plastics Engineering, Professor, Plastics Engineering, University of Massachusetts Lowell
  • Jo Ann Ratto, Research Materials Engineer, the U.S. Army Combat Capabilities Development Command Soldier Center (DEVCOM SC)

Brief Abstract:

Technically, plastics are suitable for recycling as they can be reprocessed with less energy input. However, contaminants in plastics, poor properties of recycled plastics, and sorting of plastics wastes are major drawbacks in recycling. On the other hand, blending of plastics is attractive because of the unique combination of properties of constituent polymers not available in a single polymer. For plastics recycling purposes, blending of polymers helps to minimize the need for sorting of plastics waste. One major issue of blending polymers is the immiscibility of the constituent polymers. The immiscibility of polymer blends is because of a small entropy gain from mixing which is not large enough to overcome attractive intermolecular forces. This results in weak interfacial adhesion of the phases and negatively affects the properties of the blend. To achieve compatibility of phase-separated polymer blends, techniques such as the addition of copolymers (e.g., block copolymers) reactive extrusion to graft or link different polymers together, and interfacial modification using surfactants have been studied.

Nanoparticles are materials of interest in polymer blends and recycling. They reinforce and modify the structure of polymers leaving them with improved properties. Additionally, nanoparticles have been studied to enhance the compatibility of polymer blends while improving the blend properties. This proposal seeks to understand reactive extrusion and interactions of catalysts and selected nanoparticles in different polymer systems in pursuit of improved recycling. The work completed to date begins by understanding the interaction of zeolite in low-density polyethylene during reactive extrusion and continues with compounding pretreated polymer waste with clay and ethylene-propylene rubber. Lastly, in a more complex system of real waste poly (ethylene terephthalate)/polypropylene, the interaction of modified aramid nanofiber in PET/PP blend is studied. Future work will investigate the compatibility of waste poly (ethylene terephthalate)/ polypropylene blend by incorporating montmorillonite k10 nanoclay.

All interested students and faculty members are invited to attend the online defense via remote access.