Ali Ghasemi

PhD Candidate
Marina Tsianou and Paschalis Alexandridis Research Groups

Advancing the Molecular Recycling of Plastics: Dissolution of Semicrystalline Polyolefins

Abstract

Polyolefins constitute half of the 1 trillion pounds annual global plastics production, but less than 10% is recycled and the rest is landfilled or incinerated. Dissolution/precipitation is a method that can increase polyolefin recycling, however information on polyolefin dissolution is lacking.

We investigated the dissolution kinetics of semicrystalline polyolefins through joint experiments and modeling. A phenomenological model has been developed that captures the events taking place in the dissolution of semi-crystalline polyolefin. The two key parameters of the model, disentanglement rate and decrystallization rate constant, are obtained from fits to experimental data on the time evolution of polyolefin dissolved mass (obtained from a material balance) and degree of crystallinity, quantified in real-time using a temperature-controlled Fourier Transform-Infrared (FT-IR) liquid cell. With this validated model, a parametric analysis is conducted to assess the impact of different parameters.

The insights obtained from this study facilitate the design of efficient solvent systems and processing conditions for the molecular recycling of polyolefins via dissolution/precipitation. Through this method, specific polymer types can be separated from mixtures or blends, purified from additives, and recovered for further processing, without negatively affecting the properties of the original polymers, and with minimal greenhouse gas (GHG) emissions.

Bio

Ali Ghasemi earned a B.S. degree in Mechanical Engineering-Fluid Mechanics from Shiraz University, Iran and a M.S. degree in Mechanical Engineering-Applied Mechanics from Amirkabir University of Technology, Iran. He is currently a Ph.D. candidate in the Department of Chemical and Biological Engineering at the University at Buffalo, SUNY, conducting research under the mentorship of Professors Tsianou and Alexandridis. He is investigating the dissolution of semicrystalline polyolefins through joint experiments and modeling. His findings aim to optimize solvent systems and processing conditions, advancing the molecular recycling of polyolefins from mixed plastic waste.