For sustainable society


A plastic that can be broken down at the molecular level

You will doubtless be aware that plastic waste is causing many problems such as oceanic pollution and difficulties around disposal.
We at ecoist have been introducing you to products made from seaweed and wheat bran-derived products as alternatives to plastic. A team of researchers at the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) has recently announced a new solution to the plastic issue. They have designed a next-generation renewable plastic that can be recycled many times (“Poly” or “PDK”).

Plastics contain additives such as dyes and fire-retardant substances, making it impossible to recycle most of them without losing the original performance and appearance. Even PET (polyethylene terephthalate), which is said to be the most recyclable plastic, can only achieve a recycling rate of 20 to 30 percent.

However, the PDK plastic developed by the research team is made up of monomers (the repeating units of short carbon-containing compounds) from which additives blended in can be removed by immersing the material into a highly-acid solution. In other words, it can be broken down into constituent parts and reassembled – just like Lego blocks – at the molecular level. Thanks to this, the new plastic can be used repeatedly in various shapes, textures and colors without compromising performance or quality. The PDK plastic research has been published in Nature Chemistry, a monthly scientific journal that publishes high-quality, cutting edge research papers on all aspects of chemistry.

The research team is planning to develop a PDK plastic with a wide range of applications such as textiles and 3D printing. If PDK plastic begins to be used in commercially-available products, the low recycling rate of 20 to 30 percent will surely increase. Once polluted by humans, the earth cannot be restored to its original state in a short period of time. It is our responsibility to keep it clean.