Effects of Natural and Accelerated Artificial Aging on Durability of Cold-Curing Epoxy Resins

The knowledge about the long-term behavior of materials represents one of the primary issues to be addressed to optimize their performance in service and for economic reasons as well. In particular, the lack of data about the durability of the polymeric materials can be a limit to their wider use in structural applications, such as those involved in the rehabilitation or renewal of civil infrastructures and cultural heritage. In this case, since the materials are often used outdoors, outside exposure should represent a basic reference for the study of their durability; however, many years could be necessary to produce measurable degradation and to allow the durability assessment. Numerous procedures and devices have been designed to test weathering in shorter times, although the relationship between the natural and the accelerate aging still needs to be more detailed. In this work the effects of natural weathering have been compared to those caused by accelerate artificial aging on the calorimetric and mechanical properties of different cold-curing epoxy resins. It was found that the variations in properties due to both natural exposure and accelerated aging are qualitatively similar. However, the selected accelerated aging procedure appeared excessively severe and not able to accurately reproduce the weathering occurred after outdoor exposure