Executive Summary : | Electronic waste (e-waste) generation has doubled in just five years and is presently almost 40 million tons per year. Printed circuit boards (PCB) forms a major portion of e-waste and is composed of two or three layers of non-conductive substrates, where the copper sheet is intact along with epoxy resins, fiberglass and is chemically coated with bromine epoxy layer to maintain the continuity of the circuit. The recycling rate for e-waste globally is only 15 % due to its complex nature, the presence of multiple elements, heterogeneous nature, informal collection practice, and hazards associated with the ineffective separation of plastic values from metals. The microwave absorbing characteristics of materials depend on their relative complex permittivity and complex permeability. For sufficient microwave absorbing characteristics, the metal particles should be smaller than the skin-depth for suppressing the eddy current phenomenon and these smaller particles should be uniformly dispersed in the dielectric medium to avoid agglomeration. In this lieu, particle size reduction plays an important role considering different size reduction rates of PCB components. The selection of appropriate grinding or dispersion system is quite important as they strictly control the existence of different particle morphology/shapes like rod-like structures, irregular shape, spherical, flaky which can affect significantly the performance of material especially during microwave interaction. This is because along with different shapes and sizes in an electronic waste composite material provides another additional pathway for the absorption of radar wave. The adequate presence of ~ 30-40% metals can alter the dielectric and magnetic properties of electronic waste material can be tailored for the radar absorption. The presence of metals such as Silicon, copper, and Fe can be of significant importance in the development of microwave absorption material. Besides metallic values, the other fraction rich in carbon-silicon-bromine values offers higher dielectric loss values compared to magnetic loss values; implying dielectric losses as a dominant factor for the maximum absorption of radar wave. The dielectric/magnetic constants are normally related to the chemical composition and the crystal phase of the compounds, therefore, microwave absorbers made of materials with variable composition would have different dielectric/magnetic values. Thereby, the aim of the proposal is to provide an alternative option to develop MAMs using E-waste having the properties defined by the end user. Considerable amount of resources, such as materials, time, manpower, cost, etc., will be saved if such a technique is developed. |