A review of waste-derived fillers for enhancing the properties of epoxy resins

Abstract

There is a growing interest among scientists in recycling waste materials to utilize them as fillers in polymer matrices. This approach aims to mitigate the harmful effects of waste materials and reduce costs by enhancing or maintaining various properties of polymers. Epoxy is one of the most used polymers in composite production, and research on the use of waste-derived fillers in epoxy resins has been steadily increasing over the years. These waste fillers can take the form of fibers or powders, derived from agro, bio, or industrial sources. Examples of these waste fillers can encompass a wide range of materials, from waste rubber particles to waste animal wool. In the studies from the literature, investigations of the properties were generally conducted based on filler ratio, size, treatment, and hybrid usage. Some of the properties examined include physical, mechanical, thermal, electrical, tribological, viscoelastic, wear, adhesive, and insulation properties. The present work focuses on the property improvement of epoxy resin incorporating waste-derived fillers, sourced from the literature, and categorizes them based on the effects of filler ratio, size, treatment, and hybrid usage. There are many polymer derivatives beyond epoxy and a wide variety of agro, bio, and industrial wastes globally. Consequently, this review can assist researchers in trying different characterizations, combinations and derivatives of these wastes in polymers.