Quantitative Relationship Between Color Parameters and Mechanical Property of Epoxy Resin During Thermo-Oxidative Aging

This study aims to establish a quantitative relationship between the color parameters and mechanical properties of thermo-oxidatively aged epoxy resin, with the goal of exploring a low-cost, rapid method for mechanical performance assessment based on color measurement. Epoxy resin specimens were subjected to high-temperature aging for varying durations, after which multiple color parameters were measured using a portable colorimeter. The variations in these parameters with aging duration and intensity were systematically characterized. The results indicate that during thermo-oxidative aging, strength exhibits a monotonic correlation with certain color parameters, such as lightness and hue angle. Based on this finding, an empirical model was developed to estimate strength from color parameter values. A comparison between estimated and experimental results confirms the feasibility and potential of this approach. To make the validation more convincing, it utilized not only the data from this experiment but also data from the literature. This work provides a theoretical basis and a practical technical pathway for utilizing portable colorimeter to rapidly and non-destructively assess the aging extent and mechanical performance of polymeric engineering structures.