Spherodegrade: Providing biodegradable spherical monosized polymer beads to the cosmetics market and beyond

The project purpose is to develop spherical polymer particles that biodegrade in a wastewater treatment plant to avoid microplastic pollution in nature. The particles will replace current non-degradable particles. The most important area of use is cosmetics, but other markets such as agriculture, detergents and oil and gas may also be relevant. A polymer (poly = many, meros = part) consists of many monomers. Plastics, DNA, cellulose and proteins are examples of polymers. One can design polymers in an infinite number of ways by selecting monomers that provide different properties. Like a building set, one may choose one or more monomers and combine these. So far in the project, we have used our experience combined with an extensive literature search to find as many potential monomers as possible. Candidates are assessed on the basis of the properties that these monomers are likely to contribute and whether they will be stable in water. Easily degradable polymers often dissolve in water, but since cosmetics contain a lot of water, the particles must be stable in water. The monomers must also be safe with regard to health, environment and safety and be available commercially at an acceptable price. We are now testing a wide range of promising monomers with different chemistry to better understand degradation mechanisms. In parallel, we will try to design spherical particles of the right size in the lab with the same monomers. There are a large number of polymerization techniques, but the goal is to produce the particles on a large scale, and the currently used Ugelstad process is the first priority. In the project, we have also mapped possible nearby techniques that can be adapted without large investments that can be used if the Ugelstad process prove not be feasible. If particles of the right size are achieved, the particles properties must be evaluated. The particles must degrade at an acceptable rate under the right conditions, but at the same time they must be stable during storage. And not least, they must provide the right properties in the end product.

Microplastics have gained increased attention and ECHA (European Chemical Agency) has proposed restrictions on intentional uses of microplastics in products placed on the EU/EEA market to avoid or reduce their release to the environment. This restriction may enter into force in 2022 with an extension of 6 years to reformulate the most technically demanding products. Microbeads AS needs to replace the current product range “Caché” with a biodegradable alternative. Spherodegrade aims to develop spherical, monosized polymer beads which both have acceptable material properties, shelf-life and are sufficiently biodegradable to comply with the ECHA restrictions. Caché is based on the patented Ugelstad technology which gives polymer beads with an extremely narrow particle size distribution (monosized) combined with identical chemical and physical properties, providing a competitive advantage compared to competing products. There are currently no monomer/crosslinker systems known to function in the Ugelstad process that will provide beads with acceptable biodegradability. The project aims to develop new biodegradable polymer compositions using Ugelstad process, but it might be necessary also to develop alternative production methods to succeed. It is expected to be very challenging to balance the biodegradability with the stability and material properties needed and there is a significant need for research that will be achieved by close collaboration between SINTEF and Microbeads with input on the cosmetic side from Sensient Cosmetic Technologies. With a successful project, Microbeads will broaden their product portfolio and gain innovative technologies that will allow growth in the cosmetic market and potential access into new markets. This will reduce vulnerability and strengthen competitiveness.