Thermal, Mechanical, and Morphological Properties of Rigid Crude Glycerol‐Based Polyurethane Foams Reinforced With Nanoclay and Microcrystalline Cellulose

Abstract

The enhancement of mechanical and thermal properties of rigid polyurethane foam (RPUF) achieved through a cost‐effective and sustainable approach remains an ongoing interest in both industry and academia. In this study, water‐blown rigid polyurethane (PU) foams based on crude glycerol (CG) polyol are developed and halloysite nanotubes (HN) and microcrystalline cellulose (MC) with different loadings of 1.0, 3.0, and 5.0% are incorporated to improve the performance of the foams, respectively. Effects of different loadings of HN or MC on the viscosity of CG polyols and the foaming process are investigated. CG‐based polyurethane (CGPU) foams and their foam composites (CG‐HN PU foams and CG‐MC PU foams) are characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results reveal that HN is easier to disperse uniformly in the CG polyol than MC and CGPU foams with 1.0% of HN and MC shows significantly improved performance. Their compressive strength increases by 3.8 and 12.5%, respectively, as the HN and MC loadings increases from 0 to 1.0%. The thermal conductivities of CG PU foams reinforced with 1.0% of HN and MC are 37.79 and 37.94 mWm−1K−1, which are lower than that (38.24 mWm−1K−1) of CGPU foams without the addition of fillers. Moreover, compared to CGPU foams, both CG‐HN PU foams and CG‐MC PU foams show improved thermal stabilities, and the latter is higher than the former.Practical Applications: Different fillers (HN and MC) are used to reinforce the CG‐based polyurethane, and water‐blown rigid PU biofoam composites with improved properties are prepared. The use of fillers (HN and MC) has the potential for the production of advanced CG‐based rigid PU foams.Water‐blown rigid crude glycerol‐based polyurethane foams (PU) reinforced with halloysite nanotubes (HN) and microcrystalline cellulose (MC). The results reveal that HN is easier to disperse uniformly in the CG polyol than MC and CGPU foams with 1.0% of HN and MC show significantly improved performance. The thermal conductivities of CG PU foams reinforced with 1.0% of HN and MC are 37.79 and 37.94 mWm−1K−1, which are lower than that of CGPU foams without the addition of fillers. Moreover, compared to CGPU foams, both CG‐HN PU foams and CG‐MC PU foams show improved thermal stabilities.