Evaluation of viscoelastic properties in polymer nanocomposites for prosthetic applications via microstructural profiling, model-based analysis, and dynamic mechanical thermal analysis

Abstract This study investigates the enhancement of mechanical performance and energy absorption in ultra-high-molecular-weight polyethylene (UHMWPE) nanocomposites for high-performance prosthetic applications. Nano-zeolite (NZ) nanoparticles were incorporated into UHMWPE via a scalable melt-blending process. An automated image-processing framework based on scanning electron microscopy (SEM) was developed for nanoparticle detection and sizing, employing K-means clustering, size filtering, and random forest–based diameter prediction. Dispersion analysis using the normalized span index (NSI) identified 3 wt% NZ as the optimal loading (NSI = 4.13). Dynamic mechanical thermal analysis (DMTA) revealed significant enhancements in storage modulus (E′), loss modulus (E″), and damping factor (tan δ), with the highest overall viscoelastic performance observed for the 4.5 wt% NZ nanocomposite. At 25 °C, E′, E″, and tan δ increased by 41%, 89%, and 35%, respectively, compared to neat UHMWPE, primarily due to improved polymer–filler interfacial interactions and enhanced energy dissipation mechanisms. A Bayesian-optimized Least-Squares Boosting (LSBoost) model was developed to correlate microstructural and processing parameters with viscoelastic responses, achieving high accuracy (R² ≥ 0.95, low RMSE) and identifying temperature as the dominant influencing factor. The results demonstrate the applicability of UHMWPE/nano-zeolite nanocomposites in prosthetic limb components, such as shock-absorbing joints and dynamic footbeds, where enhanced stiffness, damping, and energy dissipation are required.