Plastics

The decade that has begun in 2021 demands more and more sustainable solutions from us. And what better way to do it than based on biomimicry. Sustainable development goal number 12 of the United Nations demands the responsible production and consumption of products. It is true that plastics occupy an important part in daily life: They are part of the packaging that we use globally as well as parts for household appliances, cars, telephones, among others. Sometimes they are even part of the fibers of the clothing that dresses a large share of people. In recent years the production, mass consumption, handling and disposal of plastic material has been under constant evaluation with the aim of generating singificant improvements.

Classically, plastic production is carried out through the oil “cracking” process, which produces its basic building block, a monomer. Subsequent processes put these pieces together to form polymers such as polypropylene (PP), polyethylene (PE and PET) and polystyrene (PS). One of the environmental problems is that this process generates carbon dioxide as waste, which has adverse effects on the atmosphere. Also, the process is energy intensive by using high temperatures to create different products for which steam is employed, with its implicit carbon footprint. Once plastic is created, it is used in the packaging industry (36%), construction (16%), textiles (14%), transportation (7%), electronics (4%) and industrial machinery (1%) (407 million tons produced in 2015 in total, Naser et al 2021). Depending on the polymer used, the final products may or may not be recycled in accordance with an international universal code, which helps consumers separate them to make it easier for companies to re process it. This is a good practice as it minimizes the amount of plastic that can reach the oceans or landfills, although the process itself has a high energy cost. However, its scope has been narrow. According to Naser et al (2021), between 1950 and 2015 only 9% have been possible to recycle once and of these, only 10% more than once. Other effects on the environment are even more concerning in those cases that cannot be recycled (table 1).