• Andritsch, Thomas
• Saeedi, Istebreq A.
• Vaughan, Alun S.

Abstract

Epoxy resins are widely used as the primary insulation material in many demanding energy-related applications. As such, the ability specifically to tailor the electrical performance of such systems to meet increasingly demanding insulation situations has considerable utility. This paper describes a new approach to this problem, which is based upon the controlled introduction of specific functional groups into the cured resin's network architecture. Here, two additives are considered, termed functional network modifiers (FNM), namely glycidyl hexadecyl ether and glycidyl 4-nonylphenyl ether; in all the investigated systems, the ideal stoichiometric ratio of epoxide groups to amine hydrogens is retained. In the case of both FNM, their inclusion resulted in a progressive reduction in the glass transition temperature Tg of the system, a reduction in the real part of the permittivity and reduced dielectric losses wihin the accessible frequency range, increased DC conductivity and increased AC breakdown strength. The magnitude of the observed effects are found to be dependent upon the choice of functional modifier, which suggests that such changes are not related merely to the inclusion of an additive within the system, but are also influenced by the chemistry of the additive itself. Explanations for these effects are proposed. It is concluded that the use of such FNM at low concentrations (~4% in the work reported here) offers a novel alternative means of engineering advanced materials to meet the current and future needs in an adaptable and easily implemented manner.

Topics

• impedance spectroscopy
• inclusion
• glass
• glass
• strength
• Hydrogen
• thermogravimetry
• glass transition temperature
• resin
• amine