04. Dec 2025
Sustainable particle foams made from biopolymers
The Institute for Plastics Technology (IKT) in Stuttgart (Germany) is collaborating with the Chair of Polymer Materials in Bayreuth (Germany) to research the behaviour of modified PLA–PHA blends, particularly in the foaming process.
These are to be developed as biobased alternatives to long-established petroleum-based particle foams.
“Compared to conventional petroleum-based polymers, bioplastics such as polylactides (PLA) have a lower carbon footprint and can therefore contribute to the defossilisation of the plastics industry”, explains IKT employee Frederik Gutbrod. “However, their processing, especially in the field of foam production, is difficult due to the low melt strength of PLA. For this reason, we want to investigate in our research project how the properties of this bioplastic can be improved by blending it with other biopolymers such as polyhydroxyalkanoates (PHAs).”
There are also plans to further modify the mixtures through reactive extrusion with surface-active additives. The aim is to optimise them specifically for further processing into particle foams in order to produce a suitable foam structure with low density and small cell sizes.
“PHAs are highly biodegradable, whereas PLA is significantly less expensive. However, physically mixing these blend partners should allow the specific advantages of the individual materials to be combined in a single material. In addition to fulfilling the concept of sustainability, this approach also offers practical benefits for industry: for example, blends with different softening ranges are very advantageous for the foaming process”, emphasises Gutbrod.
“However, numerous process and material parameters influence foam production and thus the properties of the foams”, says the scientist. These complex relationships are to be described in the research project using a material model that is constantly being expanded through machine learning. The expertise in biopolymer processing and modification of IKT Director Bonten will be complemented by that in foam processing and digitalisation of Ruckdäschel, Head of the Chair of Polymer Materials (University of Bayreuth). “In the long term, we want to use this as a basis for developing sustainable particle foams that can replace conventional materials such as expanded polystyrene”, says Bonten. AT
www.ikt.uni-stuttgart.de
www.uni-bayreuth.de