What is the difference between biobased and biodegradable plastics?

There is a widespread confusion among consumers about the environmental impacts of different types of plastics. The umbrella term “bioplastics” is often used to describe very different materials, and the terms “bio-based” and “biodegradable” may be misleading[1].

Bio-based plastics are fully or partially made from biological resources, rather than fossil raw materials. However, they are not necessarily compostable or biodegradable.

On the other hand, biodegradation is a process in which micro- and other organisms degrade a substrate. These organisms are present in the environment, and they convert materials into natural substances such as water, carbon dioxide, and compost. It must be pointed out that biodegradation is highly influenced by environmental conditions.

Bio-based and biodegradable are not interchangeable terms. In consequence, different categorization groups can be established:

1. Bio-based and biodegradable plastics: among biodegradable bioplastics produced from natural sources we can find thermoplastic starch (TPS), cellulose acetate, and polyhydroxyalkanoates (PHA). Additionally, there are synthetic plastic like polylactic acid (PLA) and polybutylene succinate (PBS) than can be produced by microbial fermentation and chemical polymerization.
2. Fossil-based and biodegradable plastics: polycaprolactone (PCL) polybutylene adipate terephthalate (PBAT) are biodegradable plastics but they are produced from fossil-based resources.
3. Bio-based no biodegradable plastics: among them, the most important are polypropylene carbonate (PPC), polyethylene plastics (PEP), bio polyethylene (Bio-PE), bio polyethylene terephthalate (Bio-PET), and bio polypropylene (Bio-PP).

The current bioplastic sustainable production model relies on renewable resources derived from urban, agricultural, and food wastes. To ascertain no competition with food and agriculture resources, recent advancements are emerging to develop next-generation bioplastics derived from renewable waste streams, microbial/microalgal cells, and biomass which eventually fosters carbon neutral infrastructure for bioplastics production and management.

In this way, the production of monomers and biodegradable polymers from biomass feedstock received great attention in chemical industries, specifically through biocatalytic transformation and synthetic chemistry.

Also, there is a growing interest in novel bioplastics constituting by two or more biodegradable polymers. These materials will eventually result in the second generation of bioplastics. Hence, the final goal would be to design novel composites only made from bio-based, recyclable, and biodegradable building blocks.

[1] European Commission