Rigid PUR foam impact absorption material obtained from sustainable resources

Polyols from different sustainable resources have been widely studied as one of the raw materials for polyurethane (PUR) material production in recent years. The renewable materials have been proven as a viable alternative for petrochemical products from their properties perspective. This study describes the development of rigid PUR foam impact absorption material that was used in electric vehicle crashboxes and crossbeam system. It was a part of EU FP7 Project EVolution that's goal was to demonstrate the sustainable production of a full electric 600 kg vehicle - NidoEV. This electric car was designed by a company Pininfarina S.p.A. Lightweight materials developed in the project were used to reduce the weight of Body in White which is the heaviest vehicle element, representing about 40% of total vehicle weight. The PUR foams were obtained from polyols synthesized from sustainable resources, like rape seed oil, tall oil and recycled polyethene terephthalate. Properties, such as tensile, compression, impact, compression at high strain rates, thermal stability and morphology, were tested for rigid PUR foams.The high strain rate compression tests were done by modifying puncture impact testing equipment to obtain stress-strain curves of foam material at 100-300 s-1 strain rates. The obtained data were used by project partners to develop finite element model of crossbeam front subsystem impact behaviour into a solid wall. Proposed concept was also realized at a demonstrator level and rigid wall crash tests of the developed front subsystem were performed. Obtained results showed that such concept is a viable option for vehicle impact absorption front subsystem and sustainable materials are a suitable alternative for petrochemicals. Final weight reduction was ∼50% in respect to the steel baseline, which shows this concepts potential application in automotive industry.