Recycling polyurethane could become possible

Polyurethane recycling could become possible

An innovative new method for producing plastic from carbon dioxide

A team of chemists at the French University of Liège has developed a new technology for producing polyurethane using carbon dioxide, which is a new method that can be used to produce different types of easily recyclable plastic materials. This interesting study was published in the Journal of the American Chemistry Society.

Plastic in our lives

There is no doubt that plastic materials used in various goods have led a major transformation in global industry. Therefore, we find these plastic materials everywhere in our daily lives, to the point that their global use was estimated at about 460 million tons in 2019 alone.

The previous number is, of course, surprising, but not surprising. Because plastic – also known as synthetic polymers – has achieved great success thanks to its unique and irreplaceable properties; It is a light, cheap and incredibly versatile material, but the fact that it is difficult – and sometimes impossible – to recycle has made the scientific community hungry for sustainable solutions in this vital industry.

Plastic constitutes – on average – about 15% of the total weight of automobile manufacturing materials, a quarter of the weight of smartphone manufacturing materials, and half the weight of aircraft. In addition, it is an essential component in many value-added chains, including packaging, health care, construction, logistics services, clothing, household appliances and furniture, modern plumbing tools and pipes.

Plastics have a vital role in advancing industrial development towards creating job opportunities and developing new products. This is all for the sake of improving human life, but the more plastic is used, the greater the environmental and social costs and burdens.

The obstacles we face in plastic recycling not only lead to the depletion of the fossil resources used in its manufacture, but also lead to the long-term accumulation of huge amounts of plastic waste in nature and the oceans. Therefore, it was necessary for our society to take accelerated steps towards improving the processes of designing and manufacturing plastic materials, as they can be easily recycled at the end of their life.

In this context, the study conducted by researchers at the University of Liège – in cooperation with the University of Mons and the University of the Basque Country – revealed a new technology for producing easily recyclable polyurethane.

Turning the problem into a solution

For those who do not know, polyurethane is one of the most popular types of plastic, and is used in multiple applications, the most prominent of which is use in insulation operations; To provide durability and protection from heat, cold and corrosion for various objects and surfaces.

What makes this study interesting is the way in which the researchers were able to produce polyurethane, which is by using carbon dioxide (CO₂) – which represents a major problem for our world – as the raw material to produce the monomers (the basic building block of the polymer) needed to manufacture this polymer. Which means that they were able to transform a major problem represented by a greenhouse gas such as carbon dioxide into a sustainable solution in plastic production.

The innovative method allows researchers to modify the chemical structure of monomers; This makes it possible to produce other plastics with a wide range of properties, from very flexible materials such as silicone, to more rigid materials such as polystyrene.

The problem facing the recycling of polyurethane at the present time is its complex chemical structure, which contains three-dimensional network chemical bonds, which gives it its unique properties for use in thermal insulation processes, but this also means that the heat required to break up this complex network of bonds will lead to the burning of the material, and this is in contrast to polymers whose structure is characterized by long linear chains, which are easy to break down – melt – and reshape.

The new method of producing polyurethanes was able to transform the network of complex chemical bonds into dynamic bonds. Which means that this material can be reshaped after its production, and this is by exchanging chemical bonds under relatively mild reaction conditions.

Multiple ways to recycle

The major advantage of this new technology – as we said previously – lies in its ability to produce plastic materials with a wide range of distinctive properties, in addition to providing multiple ways to recycle these materials at the end of their lifespan. Either by melting and reshaping them, or by mixing different types of plastics to create hybrid materials with new properties, or by breaking them down into their primary monomers. The latter method is ideal for getting rid of additives that are used during plastic manufacturing processes, such as dyes.

In light of the search for solutions to exploit the huge amounts ofcarbon dioxide, this study shows that carbon dioxide waste can be used directly as a raw material for the manufacture of plastics with a wide range of properties, similar to those found in some conventional plastics, which are made from fossil sources.

The new technology for plastic production represents a major step towards transforming the plastics industry to sustainability, in addition to providing a future solution to eliminate a significant percentage of carbon dioxide emissions. Which means reducing the phenomenon of climate change, and allowing our societies to continue to rely on this unique material – plastic – for various applications and development purposes.