Tomorrow’s plastic really could be 100% recyclable and not only partially, as is the case today. Researchers from the Lawrence Berkeley National Laboratory in California have developed a type of plastic that, when simply dipped into an acidic solution at room temperature, decomposes until it “returns” to its basic elements (called monomers), free from the chemical additives that give plastic its classic look, and ready to be reassembled into any shape or color, without losing its characteristics or performance.
This extreme possibility for recycling, as reported in the scientific journal Nature Chemistry, is the result of a particular type of chemical bond between monomers (derived from hydrocarbons) that is weaker than the bond between those found in traditional plastic, and hence making separation much easier. The new type of plastic, called polydiketoenamine (PDK, in short), could therefore be an important step forward in the production of “clean” plastic and the battle against pollution, especially of the oceans.
Current types of plastic, including those that can be recycled (polyethylene), contain a wide array of substances, like elastifying components, flame retardants, dyes and many others, which bond with the monomers and form complex structures, which are difficult to separate (and hence can only be partially reused: no more than 20-30% of polyethylene, for example, can be recycled). PDK, on the other hand, frees the pure monomers made of plastic materials, depriving them – as we have said – of all other molecules, making them available for new uses.
Researchers are now trying to optimize the properties of PDK, in order to obtain sub-types to be used in textiles and in 3D printers, and to also incorporate plant-based monomers (therefore not only those made from oil derivatives): this could be another significant step towards the production of non-polluting plastics.
