Recovery and recycling of silica fabric from waste printed circuit boards to develop epoxy composite for electrical and thermal insulation applications

Abstract

Printed Circuit Boards (PCBs), a primary component of electronic waste (E-waste), contain silica fabric as a major non-metallic material, which needs to be reutilized for high-performance applications. This study focuses on the separation and recovery of silica fabrics through pyrolysis and their subsequent use in developing silica fabric-epoxy composites (SFR). Extracted silica fabric was characterized through FTIR, XRD, XPS, and SEM for morphology analysis. Subsequently, silica fabric was incorporated into epoxy to fabricate a composite with different compositions through a hand lay-up technique to achieve enhanced mechanical, thermal, and dielectric properties. The interface morphology, dielectric constant, mechanical strength, thermal conductivity, and thermal stability of composites were investigated. A strong-fabric matrix interface in composite was observed through micrographs, revealing the stress transfer through the fabric. The composition of silica fabric: epoxy (70:30) showed a high electrical resistance >30000 Ω/m, a high dielectric constant value (ɛ_r) of 4–5, and ultimate tensile strength (UTS) of 105 MPa. The thermal conductivity of epoxy was reduced from 0.35 to 0.15 W/m K after incorporating the silica fabric. This study introduces a novel method for recycling electronic waste, specifically focusing on PCBs to extract silica fabric (>95 %) through low-temperature pyrolysis (600 ⁰C) to create high-performance silica fabric-epoxy (SFR) composites. These SFR composites are suitable for several applications, including structural components and industry insulation materials such as battery boxes. This sustainable approach addresses e-waste management and enhances composite material performance, highlighting SFR epoxy composites’ versatility and research potential in various applications.