Depolymerization of nylon

The world's annual consumption of plastic materials has increased from around 5 million tonnes in the 1950s to nearly 100 million tonnes today.

For ecological but also for economical reasons, it becomes more and more important to recycle plastics. One way to accomplish this recycling is to develop depolymerization methodologies.

In this area, Kamimura and coll. has published in Organic Letters a very intriguing methodology to depolymerize nylon. They heated 6-nylon at 300°C in a ionic liquid (PP13 TFSI) in presence of DMAP as catalyst for 1h under nitrogen atmosphere until the mixture became homogeneous. After distillation with a Kugelrohr apparatus, the caprolactam was obtained in a 86% yield.

An Efficient Method To Depolymerize Polyamide Plastics: A New Use of Ionic Liquids
Akio Kamimura and Shigehiro Yamamoto
Org. Lett.; 2007; ASAP