Physics of effective media in plastic polymer-composites using Terahertz time-domain spectroscopy

Polymer composites have been an integral part of our lives for centuries and its applicability has increased substantially with recent technological advancements. However, with the vast range of available fillers and polymer materials, it is crucial to have a priori knowledge of the physical and chemical properties of the materials for various applications. Hence, material characterization at different stages of production is one of the most important parts of product development and quality control. In this article we have probed the optical behavior of a few polymer composites, with absorptive and dispersive guests, using THz time-domain spectroscopy. Subsequently, we used quasi-static effective medium theory to investigate the impact of absorptive and dispersive filler materials on the optical properties of the composites. This enables us to address the significance of filler properties on the detection limits of real-life composite compounds.