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Proceedings of Society for the Advancement of Material and Process Engineering (SAMPE) Conference 2018


In recent years, fiber-reinforced (i.e., Glass, Carbon, Kevlar) epoxy composites are used widely in structural applications ranging from military and civil aircraft production to recreational consumer products. Most of the industries use pre-impregnated varieties of composite (prepregs) to make high-quality composite parts. Despite their various advantages, prepreg materials are unstable at ambient temperature. A realistic estimation of the shelf life of prepreg is therefore essential for maintaining quality while reducing wastage of resources. Prepregs are temperature and moisture sensitive material systems. To achieve prolonged shelf life, manufacturer and seller of the prepreg must store the materials at zero degrees Celsius (32 degrees Fahrenheit) or in an even colder environment. Once exposed to room temperature or moisture, it starts to degrade and deteriorate in properties. Broadband Dielectric Spectroscopy (BbDS) is a well-known technique which is widely used for characterization of heterogeneous materials by analyzing the interaction of electromagnetic waves with matter. BbDS can give us the information about change in the molecular structure to the morphological change in the material system. In this paper, we studied the effects of degradation of prepreg at room temperature for extended periods of time and analyzed their dielectric properties using a BbDS. Later, the relationship between the dielectric properties of the pre-manufactured prepreg and the mechanical strength of the final manufactured composite parts were analyzed to establish a relation.


Engineering | Materials Science and Engineering

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The authors would like to thank the University of Texas at Arlington Research Institute (UTARI) and the Institute for Predictive Performance Methodologies (IPPM) for their financial support and laboratory equipment for the current research.