Today bioplastics, their use and their potential applications are certainly a highly topical issue; but what is actually the real meaning of the word starting from the headword mentioned in the Treccani encyclopedia: “Term used to refer to different types of plastic not produced from oil based products but with sustainable raw materials such as corn, wheat, sweet potatoes, sugarcane, seaweed, vegetable oils, etc.…”.
The main target of bioplastics is to reduce the quantity of CO2 emitted during the production process (from monomer to polymer), cutting down the environmental impact, compared to traditional plastics, with great environmental benefits.
The European Bioplastics association defines bioplastics as plastic materials derived from biomasses and consequently the right definition would be “bio-based” plastics.
The word “biomass” is referred to a very large family of raw materials sharing the natural origin and the possibility to create a substrate of fermentative processes in order to obtain valuable chemical products (proteins, ethanol). They are mainly of vegetable origin and consequently renewable resources, able to regenerate quickly (annual and/or biennial cycles) thanks to solar energy and to biochemical activity of chlorophyll photosynthesis.
Therefore bioplastics derive from monomers that are not produced from fossil resources (oil or gas) and consequently they are not renewable. It is necessary to keep in mind that non-oil-based products, despite having a natural genesis and considering that they originate from living beings (vegetables or animals), but having been transformed in geological eras, they are not considered renewable sources.
For a correct scientific interpretation and to analyse the bioplastic applications, the idea of “renewability” and the one of “biodegradability” should be split:
- renewability refers to the polymer origin;
- biodegradability refers to the polymer end of life.
Not all bioplastics are compostable, but considering they are thermoplastic polymers, also the non-biodegradable “bio-based” plastics are a 100% recyclable material at the end of their life cycle as traditional thermoplastics, as explained in the blue path in picture 1 (source European Bioplastic).