Scientists have always tried to make sure that plastics do not get dumped in the landfills after their use. Some plastics take too long to recycle which limits their reuse in several new items. However, a different kind of plastic may change this situation.
Plastics are so widely used due to their very less price, manufacturing ease and their resistance to water. The first completely synthetic plastic, bakelite was invented in 1907 by Leo Baekeland. He also coined the term ‘plastics’. The rate of slow decomposition of the plastics has led to environmental concerns.
Scientists at Lawrence Berkeley National Laboratory, United Nations Department of Energy have created a design for a completely different kind of plastic which can be broken and again built having the simplicity of a LEGO brick. The study has been published in Nature Chemistry.
According to scientist Peter Christensen, the maximum number of plastics were not made to be recycled. However, researchers have found a new technique in which the assembling of plastics is done taking the consideration of recycling at a molecular level.
Plastics are repeating chains of monomers. Monomers are the compounds which are derived from substances such as petroleum. Plastics are suitable for a wide variety of use from furniture, packaging items to straws, bags. Some plastics can be recycled easily as compared to others. Polyethylene terephthalate drinking bottles can be easily recycled but we cannot recycle plastic toys or utensils so easily.
Scientists have made some progress in the redesign of thermosetting plastics so that they can be recycled. But in order to really solve the problems with plastics, the process has to be made simpler.
The plastic developed by the Berkeley Lab can satisfy these conditions. The building block of the plastic is the monomer named as diketoenamine. This compound is created from triketone and amine. Condensation of the units results in the formation of PDK or polydiketoenamine. The interesting fact is that the bonds can be easily removed by soaking it in an acid bath for 12 hours.
Brett Helms, the team leader remarked that normal bonds of regular plastics are replaced by reversible ones which allow recycling very easily. Since the polymers can be broken down so easily, the core units of the plastics can be separated from the additives repeatedly in a closed cycle.
The recovery process has been tested repeatedly by contaminating PDK and the acidic solution with substances such as fibreglass. However, this did not impact it significantly.
Although further tests are needed for checking the suitability of PDK in various uses, the future indeed looks positive.