Everyone's after organic these days, but no one really knows what it actually means. There's more than one type of bioplastic, and they have different properties. The main things people are talking about are biobasedness and biodegradability. But there's a lot of confusion about whether fully bio-based bioplastics are biodegradable. The truth is more complicated: some bioplastics are made from fossil raw materials, but they can still be biodegradable and can be returned to the natural environment.
What does biodegradable mean?
Biodegradation is when microorganisms like bacteria and fungi break down organic materials. Bioplastics are broken down into smaller components, like water, carbon dioxide and biomass. This can happen in different environments, like soil, water or compost, depending on the conditions. The most important thing is that biodegradable plastic doesn't leave any residue behind that could harm the environment at the end of the degradation process.
The degradation process in detail
When it comes to the polybutylene succinate (PBS) we use in GC green, you can really see the biodegradation process happening in soil or compost. After six weeks of sitting in soil, a microscopic look showed that the polymer surface was pretty much gone. So, what happened was that the surface got taken over by microorganisms that were responsible for the degradation process. These guys release specific enzymes that break down the polymer chains into smaller molecules. The end result is that the molecules are fully integrated into the environment, with no harmful residues left behind.

Bioplastics and fossil materials - an interesting approach
So, bioplastics are plastics that are either biobased or biodegradable, or even both. Biobased means that the material is made entirely or partially from renewable stuff like corn or sugar cane, while biodegradable refers to the material's ability to break down in natural environments. A plastic can be bio-based but not biodegradable, or it can be biodegradable even though it's partly made from fossil sources, like with bio-PBS.
Bio-PBS is an excellent example of a bioplastic that is partly of fossil origin and at the same time highly biodegradable. It owes this property to its special polymer structure. The polymer matrix of Bio-PBS contains specific chemical bonds that are easily attacked by microorganisms. As a result, the material degrades efficiently in suitable environments. The fact that a plastic is of fossil origin is therefore not in contradiction to its biodegradability, provided the chemical structure allows this.
Advantages and applications of Bio-PBS
Bio-PBS is a pretty versatile material. It's biodegradable and robust, so it's often used in the packaging industry and for disposable products. You can use it for films, bags, food packaging and disposables in the catering sector. Because it can be broken down in certain composting facilities, it's being used more and more in packaging where people want to dispose of it in an environmentally friendly way.
Bio-PBS in our GC green compounds: it's efficient and flexible!
Our GC green compounds are made with bio-PBS, with a bio-based content of around 65-75% as standard. This mix is chosen to get the best balance between cost and sustainability. The partial fossil origin makes it cost-efficient without losing the biodegradable properties that are central to our environmentally friendly solutions. So, we offer a material that is both sustainable and economical, and can be used in various industrial applications.
If a customer asks for it, we can also provide a version of the product that's made entirely from renewable materials. This bio-PBS is currently being developed and is significantly more expensive. Customers should expect to pay around €2-3/kg more than the regular compound price for this material. Even though the fully bio-based option is currently still an investment, it shows the potential for future-oriented, fully bio-based material development and makes GC green compounds the ideal solution for particularly sustainability-conscious applications.
Biodegradable plastics and the environment
Using biodegradable plastics like bio-PBS can help cut microplastics and plastic waste. If these materials end up in the environment, they're not likely to cause long-term pollution because they break down when exposed to the right conditions. This makes them a great option for ecologically sensitive areas like agriculture or packaging, helping us move towards a more sustainable future.
Conclusion
Bio-PBS and other biodegradable bioplastics show that even materials that come from fossil fuels can be eco-friendly. The polymer structure here is what makes it happen, as it allows microorganisms to break it down. This is a big step forward for the environment, as biodegradable plastics can reduce the impact of long-term plastic pollution. Bio-PBS is an example of how materials science is innovating in response to sustainability challenges and increasing the range of biodegradable materials available.
Sources:
Hintergrundpapier Kompostierbare Kunststoffe- Biologischer Abbau im Kompost und im Boden, Verbund kompostierbare Produkte e.V., verfügbar unter www.derverbund.com
Zumstein et al., Biodegradation of synthetic polymers in soils: Tracking carbon into CO2 and microbial biomass, Artikel in Science Advances, American Association for the Advanement of Science, 2018
Nelson TF, Baumgartner R, Jaggi M et al. Biodegradation of poly(butylene succinate) in soil laboratory incubations assessed by sable carbon isotope labelling. Nat Commun 13, 5691, 2022