Development of a morphological-based predictive model for mechanical properties of binary immiscible polymer blends considering interfacial effects.

Abstract

This study aimed to develop a morphological-based model for predicting the Young's modulus and tensile strength of polymer blends with phase-separated structures. The analytical model employed the geometrical approach of the knotted and interconnected skeleton structural (KISS) model, incorporating morphological variation of immiscible polymer blends and the percolation thresholds of the components. The effect of the polymer/polymer interface on mechanical properties was accounted for by assuming a thin interfacial layer of specific thickness across the various morphological states. The prediction capability of the proposed model was evaluated using experimental data for iPP/PA, PP/PET, and LDPE/PP polymer blends, sourced from existing literature. The results established a reasonable accordance between the predicted and observed data. The model's predictions were also compared with those of established models for the tensile strength and Young's modulus of immiscible polymer blends, demonstrating its validity. Incorporating the interfacial region in the modeling procedure of mechanical properties represents a key distinguishing feature of the proposed model, enhancing its compatibility with the actual microstructure of polymer blends. Furthermore, the model's reliance on relatively simple mathematical calculations presents another crucial advantage.