Optimization of Mechanical Properties of trinary Nanocomposites Based on Polypropylene/Nitrile Rubber /Silica Nano-Powder by Using Response Surface methodology

In this study, mechanical properties including impact strength, elastic modulus and elongation at break of nanocomposites based on polypropylene/ Carboxylated Nitrile Rubber (PP/XNBR) were optimized by using response surface methodology (RSM). The samples were produced using a co-rotating twin screw extruder including 0,2,4 Wt.% of nano particles, 0, 5, 10 Wt.% of XNBR and 0,3,6 Wt.% of Polypropylene-g-glycidyl Methacrylate (PP-gMA) as compatibilizer. Impact and tensile tests were carried out to obtain impact strength, elastic modulus and elongation at break of nano composites. The results of analysis of variance showed that all three major factors silica nanoparticles, Carboxylated Nitrile Rubber and PP-gMA as compatibilizer effect on the mechanical properties with a higher probability of 90%. Also, Fisher's probable quantity values showed that silica nanoparticles had the greatest effect on the elastic modulus and XNBR had the greatest effect on impact strength and elongation at break. On the other hand, for each mechanical property, a regression model with a desirability of over 85% was obtained. Finally, the optimal values of the nano-composites were predicted to be 1.6162 wt% for silica nano powder, 10 wt% for XNBR, and 4.9697 wt% for PP-gMA.