Investigation on mechanical properties of polyurethane hybrid nanocomposite foams reinforced with roselle fibers and silica nanoparticles

The aim of this research work is to determine the mechanical, morphological and thermal properties of spherical silica (silica-A), amorphous silica (silica-B) and Roselle fiber (RF) reinforced polyurethane (PU) hybrid nanocomposites. The PU nanocomposites were fabricated with different weight percentages, 0.50 to 1 wt% for silica-A and silica-B, while 1-2 wt% for RF. These experiments were systematically designed and analyzed by response surface methodology in a central composite design approach. As per the design of the experiments, the hybrid PU nanocomposites were prepared by using a one shot process. The mathematical models developed to predict the results obtained were in good coherence with the experimental results, and were within 95% confidence levels for tensile and flexural strength. The optimum weight percentage of Roselle, silica-A and silica-B were 2, 0.78 and 1%, respectively. The optimized environmentally friendly hybrid nanocomposite demonstrated exceptional mechanical and thermal properties.