A new process can make plastics more environmentally friendly

An upcycling method changes the most widely produced plastic into the second most widely produced plastic, making it more sustainable.
Brittney Grimes
Plastic bottles.
Plastic bottles.


A new technique has been developed by scientists that transforms polyethylene (PE), the most widely produced plastic, into polypropylene (PP), the second most produced plastic.

Upcycling plastic efficiently to eliminate waste

The purpose of this process is to reduce greenhouse emissions. “The world needs more and better options for extracting the energy and molecular value from its waste plastics,” said Susannah Scott, co-lead author of the study and Distinguished Professor and Mellichamp Chair of Sustainable Catalytic Processing at UC Santa Barbara. This new study was published in the Journal of the American Chemical Society.

In the research study, Scott says there is a better way to recycle plastics besides the conventional methods currently being used. These traditional methods of recycling create low-value plastic molecules and offer little incentive to recycle the massive amounts of plastic waste that have formed over the past years.

The solution to this growing problem of synthetic waste formation is “turning polyethylene into propylene, which can then be used to make a new polymer. [This] is how we start to build a circular economy for plastics,” said Scott. According to the research, upcycling polyethylene into polypropylene can make this synthetic material into a sustainable one. This technique can improve the disposal process of plastics.

The researchers eventually want this method to create an ongoing cycle of reusability for plastics.


The team stated that this method of turning one material into another more sustainable version shows promise through its “theoretical modeling” and helps to cut the carbon footprint for the future. Researchers created a structure that allows the team to predict scalability of the project. “We have proved that it can be done experimentally in a way that is scalable and potentially applicable to current industry demands,” said Damien Guironnet, co-lead author and professor of chemical and biomolecular engineering at Illinois.

He stated, “If we are to upcycle a significant fraction of the over 100 million tons of plastic waste we generate each year, we need solutions that are highly scalable.”

The researchers also built a reactor that produces a constant flow of propylene that can be converted into PP easily using current technology, allowing for this discovery to be “scalable and rapidly implementable.” This is significant because the research team eventually wants their findings to be used on a larger scale to end pollution around the world.

Although the research has proven to be effective, the scientists would like to produce results at a faster pace. “Now that we have established the proof of concept, we can start to improve the efficiency of the process by designing catalysts that are faster and more productive, making it possible to scale up,” Scott said.

Details and discovery

The goal of this study is to advance the technological approach towards reusable plastics, specifically turning polyethylene (PE) into polypropylene (PP). In other words, how to eliminate plastic pollution and make it more eco-friendly. The researchers started with the transformation of PE, which makes up 29% of the world’s plastic consumption. They used a catalyst to turn PE into propylene, an ingredient used to create PP, which accounts for about 25% of the plastic used in the world. This breakthrough study would allow scientists to convert PP into PE, thus creating a reusable cycle for plastic and reducing plastic pollution.