Rutile Titania-Filled Polyethylene Composites: Microstructural Evolution, Empirical Modeling of the Mechanical Properties and Comparative Validation of the Quasi-Elastic Modulus Using Micromechanical Models

The effect of filling Low Density Polyethylene with mesoparticles of Rutile Titania for mechanical properties’ improvement was experimentally and numerically studied. Experimental techniques used were scanning electron microscopy, bi-axial tensile and three-point bending tests. Modeling techniques used were Least Square Polynomial Regressions, “Guth’s, Kerner’s, Hirsch’s, Halpin-Tsai’s, Halpin-Tsai-Nielsen’s and Modified Halpin-Tsai-Nielsen’s Models” encoded in Python-Shell. The prediction accuracy of the regression models was computationally validated with various statistical tests in Originlab Pro software package. The results showed micromechanics of deformation of the composites to be pronounced with craze-induced interconnected microvoids’ coalescence and dewetting-induced particle debonding at high volume fraction of filler. The composites delivered superlative enhancements of 309.85, 48.10, 12.28 and 15.12 % in tensile strength, tensile modulus, flexural strength and flexural modulus, respectively. Correspondingly, from least square regression models, specific polynomial orders showed correlations with experimental data at 0.05 null hypothesis rejection. The trend of regression model’s prediction for the quasi-elastic modulus agrees with that of the micromechanical models. However, underpredictions by most micromechanical models were attributed to the influence of unconsidered processing parameters on the models. Overall, the modified Halpin-Tsai-Nielsen evinced the greatest correlation.