Influence of the nature of curing agents, modifiers, and fillers on the functional characteristics of epoxy polymers

This article investigates the influence of the components of epoxy systems – curing agents, modifiers, and fillers – on the properties of epoxy resins, including the formation of materials exhibiting an electret state. The study examines three key aspects of epoxy composite formation: the type of curing agent, modifying additives, and fillers, as well as their impact on the structure and characteristics of the final material. It is demonstrated that curing agents determine the basic structure of the epoxy network, and the correct selection of a curing agent is essential to achieve the desired combination of mechanical and dielectric properties. By varying the type of curing agent and the curing conditions, it is possible to alter the gel fraction content. The uncrosslinked portion of the epoxy polymer can enable the orientation of dipolar groups or macromolecular segments under the influence of an external electric field, thereby inducing material polarization and yielding a chemoelectret with high electret performance. A high gel fraction content ensures the retention of the polarized state over extended storage (service) periods of the chemoelectret. Modifiers of the epoxy matrix serve for fine-tuning the properties. Increasing the modifier content in the composition alters the number of functional groups capable of polarization, which in turn affects their electret properties. Fillers are used to enhance the mechanical and functional (including electret) characteristics of epoxy compositions. It is shown that, for the creation of chemoelectrets capable of long-term charge retention, non-conductive fillers that do not form conductive pathways are preferable. Such fillers may act as charge traps while simultaneously increasing the strength of the polymer. To ensure long-term retention of the electret state, composite systems with minimal conductivity should be developed to prevent rapid charge dissipation. It may be assumed that, when creating an epoxy composite with a curing agent and a conductive filler (up to 5 vol.%), the dispersed particles act as sources of additional injected charge carriers, functioning even after the removal of the external electric field. It is concluded that the combination of epoxy resin with various curing agents, modifiers, and fillers enables the production of materials with tailored parameters. These materials can simultaneously serve as load-bearing structures and protective coatings, which is particularly relevant for modern construction challenges. Further research in the field of epoxy chemoelectrets will expand the application boundaries of these materials in construction.

epoxy composition, curing agent, modifier, filler, electret state, chemoelectret