Sustainable Shape Memory Polymer Foams

Today, polymer foams are used in numerous industries such as automotive, consumer goods, construction, medical and aerospace. The thermal and mechanical properties of water-blown polyurethane (PUR) foams can be varied over a wide range, depending on the starting materials used to produce them. After thermomechanical treatment, also known as programming, certain PUR foams exhibit a self-sufficient switching behavior during heating and cooling. This can add value and enable new applications.
Here, we introduce new polyurethane foams that are able to thermoreversibly change shape. This functionality, combined with good insulating properties, paves the way for novel concepts for material-inherent thermal management. By selecting the molecular building blocks, the switching temperature range and foam properties can be tailored. The sustainability of the materials can also be increased by customized formulations. Bio-based raw materials lead to a high proportion of renewable carbon, while the selection of linear building blocks enables the formation of thermoplastic polymers that can be mechanically recycled, for example.
The ecological impact of such materials and the thermal management concepts based on them can be estimated with the aid of life cycle assessments.
Financial support from Fraunhofer Cluster of Excellence Programmable Materials, grant number 40-03549-2500-00002, is kindly acknowledged.