Optimization of impact strength and elastic modulus of polyamide-based nanocomposites: Using particle swarm optimization method

Abstract

In the current paper, the mechanical properties of polymeric nanocomposites based on a two-phase PA6/EPDM matrix reinforced with carbon nanotubes have been optimized. The compounds consist of 0, 1, 2, and 3 wt% carbon nanotubes, 5 and 10 wt% EPDM-g-MA as a compatibilizer, and 10 and 20 wt% EPDM were made by an internal mixer. The mechanical tests were done to measure mechanical properties of the samples. In addition, SEM images were used to investigate the dispersion quality of nanotubes in the polymer matrix. From SEM findings, adding up to 2 wt% nanotubes in the matrix accompanied with a proper distribution and dispersion, whereas adding 3 wt% nanotubes into matrix results in inappropriate dispersion and agglomeration. Furthermore, samples including high level of EPDM-g-MA displayed better dispersion of nanotubes in the matrix. Moreover, the findings of mechanical tests depicted that the presence of EPDM and compatibilizing agent causes 12.5% and 22% increase in impact strength, respectively. Furthermore, the addition of nanotubes up to 2 wt% has enhanced the elastic modulus of the compounds. Finally, the optimization results of the PSO method indicate that adding 13.31 wt% EPDM, 9.91 wt% EPDM-g-MA and 2.61 wt% nanotubes progress the elastic modulus (by 36%) and impact strength (by 33%) of the matrix.