Reversible glue could help make plastic bottles easier to recycle
Researchers at Newcastle University in the United Kingdom have invented a reversible glue. It’s based on the same forces that make a balloon clingy after it’s been rubbed on hair or clothing.
As explained in a paper published in Angewandte Chemie (Applied Chemistry) International Edition, the glue is a water-based emulsion — essentially a paint — that un-bonds when exposure to highly acidic or highly alkaline water.
Until then, electrically charged long-chain molecules, or polymers, keep its electrostatic forces alive.
The inventors say the glue could offer a greener way to attach and remove labels from recyclable bottles.
Labels that are incompatible with a bottle’s plastic, or that are hard to remove, can contaminate the recycling process and render it more expensive and inefficient.
According to voluntary county reports collected by the Arizona Department of Environmental Quality, in 2019, the state recycled more than 5,000 tons of plastic.