Compressive behavior of rigid polyurethane foams nanostructured with bacterial nanocellulose at low and intermediate strain rates

Abstract

Nanocellulose reinforced foams are lightweight with improved mechanical properties; however, the strain-rate effect on theirmechanical response is not yet fully understood. In this work, rigid polyurethane foams (PUFs) nanostructured with bacterial nanocellulose at0.2 wt % (BNCF) and without it (PUF) are synthesized and subjected to compression tests at different strain rates. The BNC acts as a nucleationagent, reducing the cell size but maintaining a similar apparent density of 40.4 3.3 kg m−3. Both BNCF and PUF exhibit strain-rateeffect on yield stress and densification strain. The BNCF exhibits localized progressive crushing and reduced friability, causing a remarkablerecovery in the transverse direction. Numerical simulations show that functionally graded foams subjected to impact could be designed usingdifferent layers of PUF and BNCF to vary energy absorption and acceleration rate. The results presented herein warrant further research of themechanical properties of nanostructured foams for impact applications.