Issue 6 - Material Development
Biodegradable plastics for fishing gear
BY GAIA BIOMATERIALS (SWEDEN)
Catchgreen is working in partnership with GAIA Biomaterials, a leading biopolymer producer, in the development of a material that can replicate or exceed the performance of traditional plastic fishing gear, whilst being able to biodegrade or compost at the end of its usable lifespan – or when lost at sea. The benefits of such a material would be numerous, including the reduction of plastic pollution as macro-, meso- or microplastics, elimination of ”ghost nets”, and enhanced marine ecosystem and food supply resilience in line with global SDGs and the EU Mission: Restore our Oceans and Waters. This mission seeks to reduce plastic litter by 50% and microplastics by 30% by 2030 and has been a leading light for our project.
Key facts about Biodolomer®Ocean
Biodolomer®Ocean is a mix of PBS (polybutylene succinate) and PBAT (polybutylene adipate terephthalate)
Biodolomer®Ocean is manufactured in recognisable orange and turquoise to distinguish it from traditional fishing gear.
Biodolomer®Ocean is designed for mono-extrusion and the spinning of thread.
Biodolomer®Ocean will be used to manufacture various types of ropes and nets for fishing and aquaculture industries.
Biodolomer®Ocean
MATERIAL DEVELOPMENT
Working together with Catchgreen, R&D Manager Konrad Rosen and his team at GAIA have developed an alternative to the polyamide HDPE that is used in conventional polluting plastics in the manufacturing of fishing gear due to their useful properties – high strength, flexibility, resilience, and toughness. Our alternative, better material will need to emulate these properties, be manufactured and processed in a similar way in existing machines, perform in harsh environments for up to three years, and biodegrade in the ocean if lost or in compost if recovered at end-of-life.
GAIA has been working on a recipe that allows for durability during use yet degradation if lost at sea or during the end-of-life phase – a juggling act of the highest degree. Building on the proven success of biodegradable Biodolomer but optimizing for this application was never going to be easy, and required a rethink of the binder better suited for purpose. PBS was selected as the binder and was copolymerized with PBAT (polybutylene adipate terephthalate), another biodegradable polymer similar to fossil-based polyethylene with good flexibility and resilience.
Why PBS?
Polybutylene succinate (PBS) is a promising aliphatic polymer that can naturally biodegrade through various routes, including digestion by microbes found in the ocean. This polymer has a balanced range of properties well-suited to this application, notably thermal stability, flexibility, and ductility, as well as good processability across a wide range of temperatures.
A final grade for scale-up in 2024 is ever nearer, and although we are overjoyed with the great strides GAIA has made in bringing us the results we have we are, as always, looking forward and improving. Further development is planned before production scales, mainly focused on increasing toughness, stress, and flaw sensitivity by adding a polymeric chain extender to react with the chain ends of the PBS and increase the melt viscosity of the material.
