Time‐Temperature Superposition and Linear Viscoelastic Modeling of Talc‐Filled Polypropylene

Polypropylene (PP) is a thermoplastic polymer with a wide range of applications in the automotive industry due to its desirable properties, including low weight, cost efficiency, and high recyclability. In service, these materials are exposed to both thermal and mechanical loading. This study investigates the thermoviscoelastic behavior of three PP grades in unconditioned and thermally preconditioned states by dynamic mechanical analysis (DMA) using temperature‐frequency sweeps. The resulting temperature‐ and frequency‐dependent material response is evaluated using the time‐temperature superposition principle (TTSP). The results indicate that the investigated PP grades exhibit thermorheological complex behavior. However, restricting the shifting procedure to the storage modulus still yields comparatively smooth master curves and therefore provides an engineering‐oriented approximation of the stiffness‐related response. The observed shift behavior further suggests that talc affects the absolute stiffness level and the effective relaxation behavior of PP. In addition, thermal preconditioning predominantly influences the high reduced‐frequency response, indicating an increased stiffness contribution within the short‐time and glassy regime. The resulting shift factors are fitted by Williams–Landel–Ferry (WLF) and Arrhenius functions, with the WLF function showing slightly better agreement. A linear generalized Maxwell model (GMM) provides a good approximation of the storage modulus master curves over a broad frequency range. From an automotive perspective, the increased storage modulus, that occurs with higher talc content and thermal preconditioning, indicates a higher dynamic stiffness under short‐term loading conditions. This may affect vibration behavior and local stress levels in PP components.