Microcapsules of Biodegradable Plastics
Increased Awareness of Microplastic Downsides
The technology of micro-encapsulation is widely spread when it comes to controlled release of active substances in specific applications: For example, pharmaceutical substances are micro-encapsulated so that they can act upon selective parts of the body in a targeted way. Similarly, micro-encapsulation can significantly reduce the environmental effect of pesticides. Moreover, micro-encapsulated phase change materials are used in functional clothes as well as building materials, to maintain a feel-good temperature. In addition, many more applications exist.
However, there is another side to the coin, and that is the fact that microcapsules release plastic particles into the environment. These “microplastics” cause some problems there. The micro plastic residues are not only produced by the microcapsules themselves. They also result from secondary factors, for example interaction between the microplastic and UV radiation, or microbiological degradation.
Notwithstanding this, according to the "Technologieplattform Mikroverkapselung" (TPM, technology platform micro-encapsulation), a consortium of companies and organizations initiated by the Fraunhofer Institutes for Applied Polymer Research IAP and Chemical Technology ICT, new materials need to be developed to reduce the share of microplastics in the environment. The focus is on biodegradable materials.
Contradiction between Function and Biodegradability
The aim of reducing the amount of microplastics in the environment by means of biodegradable materials, though, is by no means trivial, in the case of micro-encapsulations. This is because, in many applications, the microcapsules’ functionalities conflict with the requirements of fast biological degradation. However, the Technology Platform says the industry is optimistic that there will be a good chance, for many applications, to enhance the small process window covering both requirements, in the coming years.