Power issues in the manufacturing and characterization of polymers and composite materials

Abstract Dynamic Mechanical Analysis (DMA), although utilized for more than three decades, has been restricted so far to material characterization rather than processing. Recently the importance of power for describing viscoelasticity in prepreg process operations has been demonstrated. This present work views DMA as an integral part of the power analysis of processes. In this study, four types of prepreg were produced under the same power of impregnation utilizing epoxy resins with various PEI contents. Prepregs were tested for compressive and toughness power as well as loss power. Laminates were developed and analyzed by DMA. DMA data was treated according to the established power methodology and compared with the tack power of the original prepreg. Specific compressive power was generally found to increase with increasing storage DMA power, while specific toughness power was found to show the opposite trend. The inverse of power, defined as tolerance, was also investigated. The out‐of‐phase DMA tolerance was found to correlate to loss prepreg power, bringing a deeper understanding to the fundamentals of viscoelasticity formation. This analytical methodology can be applied beneficially to many topics to provide a better understanding of polymers and composites, as well as smart materials.