Designing the Death of a Plastic
https://www.NYTimes.com/2018/08/06/science/plastics-polymers-pollution.html That is, designing self-destructing polymers
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“Dr. Feinberg’s polymers were imprisoned in circular loops instead of being open-ended chains. By themselves, the loops were stable. For the self-destructing plastic, Dr. Feinberg mixed the polymers with a little bit of yellow, light-sensitive dye. When light shines on the plastic, the energized dye molecules rip electrons out from the polymers. The loops break, exposing the polymer ends, and the polymers unzip.
Other scientists trap their polymers by capping the ends of the long chains or linking the chains together into networks. By designing these traps to fail upon meeting certain triggers like light or acid, scientists can control exactly how and when their polymers unzip.
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In theory, these next-generation polymers could help mitigate pollution problems associated with plastic products. If the units were collected after unzipping to make new polymers, that would lead to chemical recycling. Most recycling done today simply involves melting the plastic and remolding it.
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Economically speaking, replacing the most widely used polymers like polyethylene (grocery bags), polypropylene (fishing nets) or polyterephthalate (single-use bottles) with unzipping polymers is not feasible.
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