Determinação do fator de mudança de tempo-temperatura para previsão de vida a longo prazo de compósitos e resinas epóxi por DMA

Abstract

The present study presents the result of the construction of the master curve by dynamic mechanical analysis (DMA) in unidirectional composites of glass fiber and epoxy resin classes F and H to evaluate the thermal stability and durability of these materials. To this end, the viscoelastic behavior of polymers and composites was evaluated using the time-temperature superposition (TTS) model of Williams, Landel and Ferry (WLF), which allows the extension of experimentally accessible frequencies and the description of the entire relaxation behavior of polymers. The time-temperature change factor was determined by dynamic mechanical analysis (DMA) curves, in individual isotherms under the condition of different oscillation frequencies. It has been observed that viscoelastic behavior depends on frequency and temperature, and there is a general equivalence between frequency- and temperature-related behavior during transition processes. The composite materials manufactured by filament winding were also subjected to physical and thermal characterization, ensuring the compatible quality of high-performance structural composites. Once the time-temperature change factors have been described by the model, the master curve can be transposed to any desired temperature value, reducing the number of empirical testings.