Experimental determination of mechanical properties of PMMA reinforced with functionalized CNTs

The main challenges in successfully using CNTs as a reinforcement phase in a composite are homogenous dispersion and distribution of the CNTs in the matrix, as well as improving the interfacial bond between them. Functionalization of CNTs has proved an effective method for overcoming these challenges. The goal of this study is to determine the mechanical properties of a composite material using experimental methods. The composite consists of a poly(methyl methacrylate), or PMMA, matrix enhanced by different weight fractions (wt%) of nanotubes functionalized by two methods. Carboxylated CNTs were further functionalized by the grafting from (GF) and the grafting to (GT) methods. The effect of these functionalization methods on the CNTs is evaluated through measurement of effective mechanical properties of a composite containing them, as well as, through a comparison to a previous investigation, in which non-functionalized (NF) CNTs were employed. Tensile tests were carried out on neat PMMA and PMMA containing functionalized CNTS; there were two GF batches containing 0.8 wt% and 1.5 wt% of CNTs; and three GT batches containing 1.5 wt%, 3 wt% and 6 wt% of CNTs.