Effect of Temperature on Mechanical Properties of Nanoclay-Reinforced Polymeric Nanocomposites. I: Experimental Results

Abstract

In this paper, the effect of temperature and nanoclay reinforcement percentage on nanoclay-reinforced polymeric nanocomposites is studied. First, polypropylene (PP 3371) resin reinforced with various nanoclay percentages is tested at room, elevated, and low temperatures. The tests are conducted on ASTM Type I specimens instrumented with strain gauges in a material testing system machine equipped with an environmental chamber. Next, to ascertain the effect of various PP resins, nanoclay-reinforced Borealis and total petrochemical (TP 3868) tensile specimens are tested from low to elevated temperatures. In addition, nanoclay-reinforced epoxy specimens are tested at room temperature. The test results are plotted as stress-strain curves and the mechanical properties of the nanocomposites including the Young’s modulus, Poisson’s ratio, ultimate stress, and failure strain are determined. The tensile test results indicate that the Young’s modulus of the nanocomposite increases with increasing nanoclay reinforcement percentage. The temperature has even a more significant effect. It was observed that as the temperature decreases the material becomes brittle, has higher stiffness, and fails at lower strains. High temperatures have the opposite effect. As the temperature increases the material loses stiffness and becomes more ductile. Temperature and nanoclay reinforcement also affect the Poisson’s ratio but this effect is less significant. In general, as the temperature increases the Poisson’s ratio also increases. However, an increase in nanoclay reinforcement generally reduces the Poisson’s ratio. It is also noted that the type of resin used may have a significant effect on the mechanical properties of the nanocomposite.