"We must give bioplastics a chance«
Compostable garbage bags and food packaging made of bio-PE have nothing in common chemically. Nevertheless, both count as “bioplastics”. In an interview with "Spektrum", the polymer researchers Frederik Wurm and Hans-Josef Endres discuss the sense and nonsense of biodegradable and bio-based plastic.
"Spectrum": How do you like the term "bioplastic"?
Hans-Josef Endres: The term itself is not bad, but you shouldn't use it alone. Two adjectives are important here: "biodegradable" or "bio-based". One is not synonymous with the other.
Bio-based polyethylene (PE) is chemically simply polyethylene, with exactly the same structure and properties. Of course, this means that a bio-based PE is not biodegradable. There are many other prominent examples of such plastics: linoleum, for example, or tires made from natural latex. A number of well-known materials were developed before petroleum was available. They were biobased but not biodegradable.
You can also build biodegradable molecular structures from petrochemical raw materials. The third group are materials that have both properties, such as plastics based on starch or lactic acid.
Where do the renewable raw materials for the plastic come from?
Endres: A number of resources can be used for this purpose. They can be produced agriculturally, like starch and sugar or vegetable oils, which are needed for polyamides or polyurethanes…