A model for tensile strength of cellulose nanocrystals polymer nanocomposites

Cellulose nanocrystals (CNCs) are rod-shaped, highly crystalline, and possess a high aspect ratio, extensive surface area, and exceptional mechanical properties, making them ideal for reinforcing polymer matrices. However, few models exist for predicting the mechanical properties of CNC-based polymer nanocomposites (PNCs). Existing models often overlook the interphase's role in the mechanical performance of CNC-filled samples, leading to unreliable predictions. This study introduces a straightforward model emphasizing the interphase region and CNC properties to determine the strength of CNC-based system. The model is validated by experimental data and parametric analyses. The results indicate that interphase thickness and strength depending on the interfacial bonds between polymer chains and CNCs along with CNC volume fraction directly control the nanocomposite strength, while a larger CNC diameter diminishes it. Optimal strength in PNCs is achieved with thinner CNCs, thicker and stronger interphase, and higher CNC content. In addition, numerous experimental outputs of various samples show good fitting with model's predictions.