Mechanical Properties of Micro/Nanocellulose-Filled Epoxy Sheets at Subzero and Elevated Temperatures

Due to their low cost and 100% biodegradability, nanocellulose fibrils derived from wood can serve as a filler in polymer sheets. In this study, micro/nanocellulose fibrils were obtained after Lab Valley beater (LVB) and Super masscolloider (SMC) refining. The LVB refining was carried out for 20 min at 0 clearance (LVB_0_20), and SMC refining was carried out for 60 min at 0.1 and 0 clearances (SMC_0.1_60 and SMC_0_60), and nonwoven sheets were fabricated using a vacuum filtration. These micro/nanocellulose-filled epoxy nonwoven sheets were processed by the hand layup/vacuum bagging and cured at 160 °C for 3 h. The tensile properties of filled epoxy sheets were measured at -20 °C, 23 °C, and 80 °C, and it was found that the SMC_0_60_epoxy sheet revealed high modulus at all temperatures compared to other sheets, but its strength and work-to-fracture values are found to be low at 80 °C compared to -20 °C. SMC_epoxy sheets have high tensile strength compared to LVB_epoxy sheets due to the presence of nanocellulose fibrils. The tensile fractography was carried out using SEM. Filled epoxy sheets revealed 45-70% higher thermal conductivity and slightly lower weight loss at 430 °C compared to epoxy, making these sheets useful in developing optimum strength and partially biodegradable thermal packaging components.