Simulation of interphase strength to estimate the tensile strength of cellulose nanocrystal-reinforced polymer nanocomposites

This paper presents a simple and novel method for determining the relative strength ( σ R ) and interphase strength ( σ i ) of cellulose nanocrystal (CNC)-based polymer nanocomposites (PNCs). The proposed approach uses the modified Pukanszky model, in which the interaction parameter B reflects the efficacy of load transfer from the matrix to CNCs. The progressed model enables the calculation of interphase properties for various CNC-based PNCs, and its accuracy is validated through comparison with tensile strength data of many samples. This novel methodology is further used to explore how variations in interphase properties and CNC geometry specifically CNC length ( l ), CNC diameter ( d ), CNC volume fraction, interfacial stress transfer parameter ( s ), and interphase thickness ( t ) affect the strengths of interphase and nanocomposite. The results show that σ i increases with higher t and smaller d . A peak value of σ i = 200 MPa is attained under optimized interfacial and geometric conditions ( s = 4 MPa and CNC aspect ratio of 100), whereas σ i = 20 MPa is predicted at weak interfacial interactions ( s < 1 MPa) or low aspect ratios (< 45), confirming the strong sensitivity of σ i to interfacial and CNC-related parameters. For σ R , the model predicts the supreme σ R = 9 (800% enhancement in the PNC strength) when t = 10 nm and d = 3 nm. Optimizing these parameters offers a pathway to improve both interphase quality and overall composite strength. The development of such predictive models may support the rational design of high-performance products for multipurpose applications.