Modeling and optimization of a new impact-toughened epoxy nanocomposite using response surface methodology

This paper reports the development of a high-impact epoxy nanocomposite toughened by the combination of poly(acrylonitrile-co-butadiene-co-styrene) (ABS) as thermoplastic, clay as layered nanofiller, and nano-TiO₂ as particulate nanofiller. Response surface methodology (RSM) was applied for optimization and modeling of the impact strength of epoxy/ABS/clay/TiO₂ quaternary nanocomposite. A second-order mathematical model between the response (impact strength) and variables (ABS, clay and nano-TiO₂ contents) was derived. Analysis of variance (ANOVA) showed a high coefficient of determination value (R ² = 98%). Under optimum conditions, maximum impact strength of 29.2 KJ/m² with 197% increase compared to neat epoxy was experimentally obtained. Also correlation between morphology and impact strength of the nanocomposite was investigated using scanning electron microscopy (SEM) and X-ray diffraction (XRD). A dispersion of exfoliated clay platelets, TiO₂ nanoparticles with low agglomeration and ABS nanoparticles was obtained as morphology of the nanocomposite. A new and more effective method for impact toughening of epoxy was introduced. This study clearly showed that the addition of the combination of layered and particulate nanofillers along with ABS as thermoplastic has a considerable enhancement effect on impact strength of epoxy.