You’ll typically hear plastic contamination described as an issue. The truth is that it’s numerous issues. Depending upon the homes we require, we form plastics out of various polymers, each of which is held together by an unique kind of chemical bond. The approach we utilize to break down one type of polymer might be incompatible with the chemistry of another.

That issue is why, although we’ve had success finding enzymes that break down typical plastics like polyesters and PET, they’re just partial options to plastic waste. Scientists aren’t sitting back and basking in the victory of partial options, and they’ve now got extremely advanced protein style tools to assist them out.

That’s the story behind an entirely brand-new enzyme that scientists established to break down polyurethane, the polymer typically utilized to make foam cushioning, to name a few things. The brand-new enzyme works with an industrial-style recycling procedure that breaks the polymer down into its fundamental foundation, which can be utilized to form fresh polyurethane.

Breaking down polyurethane

The brand-new paper that explains the advancement of this enzyme sets out the scale of the issue: In 2024, we made 22 million metric lots of polyurethane. The urethane bond that specifies these includes a nitrogen bonded to a carbon that in turn is bonded to 2 oxygens, among which links into the remainder of the polymer. The remainder of the polymer, connected by these bonds, can be relatively intricate and frequently includes ringed structures connected to benzene.

Absorbing polyurethanes is challenging. Specific polymer chains are frequently thoroughly cross-linked, and the large structures can make it hard for enzymes to get at the bonds they can absorb. A chemical called diethylene glycol can partly break these particles down, however just at raised temperature levels. And it leaves a complex mess of chemicals that can’t be fed back into any helpful responses. Rather, it’s normally incinerated as contaminated materials.