Degradation of bioplastics in different environments

The project aims to answer the following question: are PHA-based products as safe as expected?

This includes the following subquestions: 

• Will PHA-microplastics form in the environment?
• What is the lifecycle of these microplastics?  
• Are they formed through fragmentation or microbial degradation?  
• Does the process affect soil health?

A second research question is: Can PHA products be recycled at the end of their life cycle? 

This includes the following subquestions: 

• What degradation products are formed when PHA products degrade in a natural environment? 
• Are these degradation products reusable for new PHA polymers? (Recycling) 
• Can these degradation products be reused as feedstock for bacteria to produce new PHA polymers? (Recycling) 
• Are these breakdown products also suitable for other applications? (Repurposing) 

In this project, researchers are working towards the following goals:

• Better understand the degradation process of PHAs in natural environments
• Mapping the impact of the degradation products on natural ecosystems
• Stimulate biodegradation by bio-augmentation (by using microorganisms with PHA-degrading properties)
• Explore opportunities for degradation-on-command of PHA-based products
• Understanding whether and how degradation products can be (re)used

With the project, we expect to gain the following insights:

• Results on degradation per gram of PHA per unit of time
• Finding, isolating and characterising microorganisms with PHA degradation properties
• Insights on the effect of PHA degradation products on the natural environment
• Results on the use of degradation products of PHA as a new raw material, making PHA a fully circular product

Current fossil plastics are a major problem for our climate, natural ecosystems, and our health. Traditional plastics are based on fossil fuels, and break down into microplastics. These microplastics end up in the sea and soil, negatively affecting these ecosystems.

Biodegradable plastics based on renewable resources are a sustainable alternative to fossil plastics. These plastics are made from biobased materials, namely biopolymers. A biopolymer such as PHA is biodegradable. PHA-based plastics (and blends with PHA) are therefore less harmful to the environment, but exactly what effect the degradation products have is not yet completely clear. This project monitors the degradation per gram of PHA per unit of time. PHA products from industry partners are used for this purpose.

With the results of this project, we will learn whether the degradation of bioplastics has a negative effect on the natural environment, including a marine environment and agricultural land. We are looking at how to promote degradation by deploying micro-organisms with PHA-degrading properties. Thus, future microplastics can be avoided, ensuring a healthier natural environment.

To test the degradation of PHA, we will work together with a manufacturer of PHA (Paques Biomaterials B.V.) and producers of PHA products (Happy Cups B.V. and Maan Group) will be involved in the project. The results of the research will thus be directly applied to practical applications. 

With the knowledge gained in this project, we can increase the industry's trust in circular, biobased plastics for a range of applications. The complete life cycle, from production to degradation and reuse of degradation products, will be mapped. This will allow producers to better assess the impact of their products, and ensure that they comply with (future) laws and regulations on sustainability and circularity.