The effect of the size and shape of alumina nanofillers on the mechanical behavior of PMMA matrix composites

Composites with the addition of alumina nanofillers show improve- ment in mechanical properties.Poly(methyl methacrylate), PMMA, was used as a matrix and two different types of nanofillers having extremely different shapes were added into the matrix to form the composites. The reinforcements were based on alumina nanoparticles having either a spherical shape or whis- kers with a length to diameter ratio of 100. The influence of the size and shape of the alumina fillers and the loading on the mechanical properties of the pre- pared composite were studied using nanoindentation measurements and dyna- mic mechanical analysis. It was observed that both alumina whiskers and sphe- rical alumina nanoparticles added in the PMMA matrix improved the mecha- nical properties of the composites, but the improvement was significantly higher with reinforcement by alumina whiskers. The concentration of the rein- forcing spherical alumina nanoparticles and alumina whiskers in the PMMA matrix varied up to 5 wt. %. The best performance was obtained by the addi- tion of 3 wt. % of alumina whiskers in the PMMA matrix in terms of the mechanical properties of the obtained composite.