Towards precision in nanocomposite design: Predictive model for tensile modulus of polymer starch nanocrystals system by interphase features

This study proposes a sophisticated model for predicting the tensile modulus for polymer starch nanocomposites (PSNCs) using the Hui-Shia equation, which integrates the effects of interphase regions surrounding platelet starch nanocrystals (SNCs). The model efficacy is evaluated by juxtaposing its predictions with experimental data. The results reveal that neglecting the interphase leads to pronounced discrepancies between experimented observations and theoretical calculations. Conversely, the inclusion of interphase region within the proposed model results in highly accurate predictions of tensile modulus particularly at the low percentage of SNCs. The significant influences exerted by the volume fraction, length, and thickness (t) of SNCs, interphase thickness (t_i), interphase volume concentration, and the aspect ratio of nanoparticles on the tensile modulus of PSNCs are analyzed. The maximum enhancement of PSNC modulus as 37 % is yielded at t = 5 nm, but the increment of t has an undesirable effect on the stiffness. Furthermore, the densest interphase surrounding the SNCs (t_i = 20 nm) facilitates a notable 38 % increase in the modulus of the PSNC, while the absence of interphase cannot improve the stiffness. The stimuli of all factors on the modulus of PSNCs are plotted and justified to corroborate the proposed model.