Reinforcing Natural Rubber with Cellulose Nanofibrils Extracted from Bleached Eucalyptus Kraft Pulp

Abstract

Reinforced natural rubber (NR) nanocomposites were prepared by solution mixing. casting. and evaporation of pre-vulcanized natural rubber latex and an aqueous suspension of cellulose nanofibrils (CNFs) extracted from bleached eucalyptus kraft pulp. Scanning electron microscopy (SEM) images showed that there were no micro-scaled aggregates observed in the nanocomposites. The addition of CNFs changed the mechanical behavior of the nanocomposites as observed in tensile tests. The tensile strength was significantly enhanced with CNFs, but the material became brittle at higher CNFs loading levels. Dynamic mechanical analysis (DMA) proved the strong reinforcing tendency of CNFs in the NR matrix as the storage modulus of the nanocomposites increased with CNFs content across the entire temperature range. Thermal gravimetric analysis (TGA) showed that CNFs had a slightly negative impact on the thermal stability of NR nanocomposites. There was no change in the glass transition temperature of the rubber matrix with the addition of cellulose nanofibrils, which was characterized by differential scanning calorimetry (DSC) measurements.