Azernews.Az

By Alimat Aliyeva

Scientists at the University of Buffalo (USA) have developed an innovative method for recycling flexible plastics, which could significantly expand the possibilities for reusing the most common types of plastics—polyethylene (PE) and polypropylene (PP), AzerNEWS reports.

The findings of the study have been published in the journals Polymers, International Journal of Heat and Mass Transfer, and Journal of Polymer Science.

Polyethylene and polypropylene are part of the polyolefin family, the most widely used plastics in the world. They are found in packaging, food containers, plastic films, and various other materials. However, flexible plastic films remain among the most difficult types of waste to recycle because they do not respond well to traditional mechanical recycling methods and often end up in landfills or polluting the environment.

According to recent statistics, in 2024, over 359 million tons of plastic were produced worldwide, with polyolefins accounting for more than half of this volume.

A team of researchers led by Professor of Chemical Engineering Pascal Alexandridis is investigating solvent-based recycling technology. The method involves dissolving plastic materials in specially selected solvents, then isolating purified polymers from the solution. This approach allows polyolefins to be separated from multilayer materials while removing additives and impurities.

Professor Alexandridis explains that this solvent-based method opens new avenues for efficient plastic waste management, enabling useful materials to re-enter the economic cycle. Unlike pyrolysis, which breaks down plastics thermally, this approach preserves polymer chains, making the resulting material reusable in new products.

To optimize the technology, the researchers examined polymer dissolution at the microscopic level, combining laboratory experiments with computer modeling. They discovered that polypropylene granules first lose their crystalline structure, after which the dissolution process begins. They also developed a model for polyethylene dissolution, allowing them to predict how different polymer regions behave and how solvents penetrate at various temperatures. Additionally, a specialized experimental setup enables real-time observation of polyethylene’s structural changes using infrared spectroscopy.

The team believes that this technology could complement existing recycling methods. Currently, less than 10% of plastic waste is recycled worldwide, largely due to complex multilayer materials that are difficult to separate. Solvent-based recycling could purify polymers and return them to production, reducing plastic disposal and incineration.

Interestingly, the principles behind this research could have applications beyond recycling. For instance, they could help in developing advanced polymer materials or controlled drug delivery systems, demonstrating how innovations in one field can ripple across others.