Manufacturing and Modeling of Hybrid Polymer Composites by Using Multiple-nonlinear Regression Analysis

In this study, artichoke stem particles (AS) and wollastonite mineral (W) were used as an organic and inorganic fillers in order to improve the mechanical properties of polypropylene (PP). In this regard, PP-based composites containing AS and W were produced as non-hybrid and hybrid materials using a high-speed thermokinetic mixer. Mechanical properties of polymer composites were investigated by the tensile test. Experimental results reveal that the highest elastic modulus for PP-W and the highest tensile strength for PP were obtained while the lowest ultimate strain value was gained using PP-W-A. Then, multiple nonlinear regression analysis was employed to determine the effect of weight ratios of wollastonite mineral and artichoke stem particles in polypropylene on elastic modulus, tensile strength and ultimate strain. Experimental results were expressed second order (tensile strength), third order (elastic modulus) and fourth order (ultimate strain) mathematical models. The results show that the proposed models have well fitted with the experimental results. The coefficient of determination (R2) values were found between 0.95 and 1 in all models. Also, boundedness check control of the proposed models which gives information about whether models are realistic or not was carried out by calculating the maximum and minimum values produced by the relevant model.