Circular bio-based polymers for the construction industry

The entire construction industry in general, but also building services engineering and supply technology in particular, have a great potential for optimization in terms of their greenhouse gas emissions and waste generation, as they are responsible for more than a third of the global greenhouse gas emissions. One way in which this proportion can be reduced is by replacing petrochemical raw materials in polymer components with bio-based base materials. Bio-based plastics can make a significant contribution to resource efficiency and the circular economy, especially if they are produced regionally, used and reused or recycled sensibly. In the CircularBioMat project we want to minimize the environmental footprint by substituting petroleum-based polymers with bio-based polymers for building services engineering. First, we
evaluated the used oil-based materials and together with the project partner suitable bio-based polymers were selected. In a further step we characterised the oil- and bio-based polyethylene PE with High Pressure Capillary Rheometer for viscosity, Differential Scanning Calorimetry for thermal properties and pvT measurements. One bio based material CBM 1 matches the viscosity of both PE IM for injection moulding and PE EX for extrusion quite well, while the CBM 2 is expected to have a lower zero shear viscosity. The DSC shows similar melting behaviour, only the degree of crystallinity differs, especially CBM 1 shows a lower normalized enthalpy. The specific volume is different in all polymers, only the CBM 1 matches the PE Ex in the solid region, while in the melting it has a higher specific volume. In a further step we made recycling trials by injecting molding and grinding the materials ten times and we analysed the viscosity with a cone and plate rheometer to observe changes in the zero shear viscosity and especially the cross over point. The mechanical behaviour is tested by tensile testing for different recycling steps by a partner