Cellulose nanocrystal reinforced acylglycerol-based polyurethane foams

Abstract

This work presents the preparation of polyurethane composite foams based on castor oil or modified canola oil as a polyol, and cellulose nanocrystals (CN) as nanofiller (0.10, 0.25, and 0.50 wt% of CN content). The bio-based composites were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), and mechanical properties. The SEM images showed that composite foams had smaller cell sizes and more irregular than those observed for unloaded samples. FTIR revealed that the urethane/urea bond formation was influenced by the incorporation of CN, and was dependent on the polyol used in the formulation. The incorporation of CN did not affect the thermal stability, but the density and mechanical properties changed differently depending on the selected polyol. These results suggested that the acylglycerol structure affects the role of CN in the formulation. Also, the proliferation of MC3T3-E1 preosteoblastic cells showed that the cell viability of polyurethane bionanocomposite foams increased significantly in comparison to the unloaded material.