Modification of resin/hardener stoichiometry using POSS and its effect on the dielectric properties of epoxy resin systems

摘要

The effect of changing the network architecture on the thermal and dielectric properties of an epoxy resin systems is described. The stoichiometry was controlled by introducing a reactive diluent which features multiple epoxide groups within its chemical structure. Therefore, by calculating the number of epoxide groups supplied by both the diluent and the resin, the stoichiometry and the resultant properties were varied. The DSC measurements indicated a reduction in the glass transition temperature (T_g) of systems with excess epoxide groups, while the dielectric measurements showed increased permittivity compared to the theoretical optimum stoichiometry system. Thus, the epoxy/hardener stoichiometry affects the dielectric and thermal properties of the systems, whereby changing the stoichiometry would allow manufacturing of insulating materials with optimized properties. However, the optimum stoichiometry is dependent on the material property of interest.