Lawrence Berkeley National Laboratory, owned by the United States Department of Energy, created a new kind of polymer material. This material, by the type of designers, is disassembled and assembled, taking the necessary shape, density and color shade without loss of quality. This polymer was called polydiketoenamine, abbreviated PDK.
Plastic produced worldwide is mainly not to be reused. Experts have applied a new method in production, with which you can take into account the molecular processing of the product.
The well-known and most common at the moment plastic PET (polyethylene terephthalate) is suitable for processing by only 25%. All the remaining amount is in incinerators, landfills or settles in soil and water bodies.
Plastic usually consists of long, carbon-based molecular molecules that are linked together to form polymers. Due to their structure, they exhibit chemical stability - that is, they are not susceptible to corrosion. To adapt the material to a specific use, other chemical components are added to it at the plants. For example, additives are necessary in order to make plastic softer or, conversely, denser. Subsequently, such additives can no longer be removed from the composition, even with specialized processing of plastics.
Materials with different chemical components are mixed, combined and melted during the processing process. The properties of re-obtained plastic are almost impossible to predict.
Plastic recycling is a huge problem all over the world. Now the issue of ecosystem pollution is everywhere being raised, and most likely we will have to expect a worsening of the situation, as the amount of unused and produced plastic continues to grow.
It turns out that the monomers that make up the PDK are easily removed by simply immersing the material in a strongly acidic liquid, in which the bonds between the monomers and additional components are broken.
Scientists have discovered this ability of PDK when applying various acids to glass containers used for the preparation of adhesive mixtures. Specialists noticed that the glue was changing. This forced them to analyze plastic by nuclear magnetic resonance and spectroscopy, due to which the originality of the monomers was discovered.
Further experiments demonstrated that the acidic environment cleaves PDK polymers into monomers, while simultaneously separating them from additional molecules. In this case, the monomers can be re-converted into polymers, which after processing will be completely purified from other components. Experts suggest that a new type of plastic can become a promising analogue of other materials that are not recyclable.
Experts have already planned the development of PDK plastics, which have an extensive range of thermomechanical capabilities, for subsequent use in the textile and 3D printing industries. It is also planned to manufacture new types of plastic from plant and environmentally friendly materials.
Details of the work were presented on the pages of Nature Chemistry (www.nature.com/articles/s41557-019-0249-2).