Today's KNOWLEDGE Share : Alabama lab cooks up powerful solution for plastic scrap:

Today's KNOWLEDGE Share

The University of Alabama has scored a breakthrough that could be a recycling game-changer for multiple types of plastics.

‘Plastic recycling is commonplace but imperfect,’ says Dr. Jason Bara, who leads a PET depolymerisation R&D project at the university. He had been working with amines for a couple of years to break down plastics as part of a National Science Foundation grant in an attempt to reduce plastic waste. Recently, he tried a new approach ‘just to see what would happen’.

‘The plastic is gone’

A key to his discovery is imidazole and its related compounds; a group of organic molecules that have proven to be highly effective in the chemolysis process.

Previously, plastic depolymerisation had been achieved using water, alcohols, and amines. Bara notes that nothing in the literature pointed to the power of imidazoles as a recycling agent.

‘I’ve been working with imidazole for much of my career. It’s pretty amazing how versatile it is,’ he says. One day, one of his students came into the lab and told him the plastic they had been doing tests on was simply gone.

Patent pending

The University of Alabama has filed a patent application for the innovative PET recycling process. Bara says it offers several key advantages over other chemical recycling methods, including the lack of additional solvents or catalyst. This is due to the relatively low melting point of imidazole.

Bara underlines this is a great quality for developing a cost efficient and commercially viable process. He adds that the new method is unique in that it’s a flexible recycling technology. ‘You can get a wider range of final products from PET depolymerisation when you do it our way,’ he explains.

Beyond PET

Bara is excited about the new opportunities his research may unlock. For example, recent tests have demonstrated that imidazolysis is also useful in depolymerising polyurethanes. These are more difficult to process than PET.

What’s challenging is that polyurethanes are generally made into foam products that are full of air, do not melt and contain a large number of inorganic additives.

‘Our process could increase the recycling of polyurethane foam, which is widely used a variety of consumer products – ranging from packing foams, seat cushions, memory foam mattresses to automobile seats,’ Bara says.

‘While I think what we’ve already published on the successful imidazolysis of PET is very exciting, the chemical recycling of polyurethanes is where imidazolysis may potentially have a much bigger impact.’

source:University of Alabama / www.recyclinginternational.com