Multi-response optimization of impact strength and elongation at break of nanocomposites based on polypropylene/polyethylene binary polymer matrix in the presence of titanium dioxide nanofiller

In this article, the effect of adding titanium dioxide (TiO₂) nanoparticles on impact strength and elongation at break of polypropylene/linear low-density polyethylene (PP/LLDPE) binary polymer matrix has been investigated. A 2³ factorial design analysis was conducted to screen significant factors influencing the impact strength and elongation at break of polymer nanocomposites based on PP/LLDPE matrix. Three factors in two levels including LLDPE at 20 and 40 wt%, TiO₂ nanoparticles at 2 and 4 wt%, and styrene–ethylene–butylene–styrene (SEBS as coupling agent) at 0 and 3 wt% were chosen for adding to matrix, and eight experiments were conducted for each response. Optimization of these factors was done for predicting maximum impact strength and elongation at break. It was observed that nanoparticles decreased impact strength. The presence of high levels of LLDPE and SEBS led to an increase in impact strength and elongation at break. From the analysis of variance, the most important parameters affecting impact strength and elongation at break were determined, and satisfactory prediction regression models were derived. In addition, the optimal condition of LLDPE and SEBS for the best combination of response variables was obtained at high level and for TiO₂ at middle level.