Ionic doping of low conductivity structural resins for improved direct current sensing

This investigation developed a methodology for doping high resistivity vinyl-ester resins with an organic dopant to increase ionic conductivity. The polymeric resin system investigated was a Dow Derakane 411-C50 vinyl-ester (VE) resin. A number of potential dopants were studied and two in particular, tetrabutylammonium acetate and tetrabutylammonium iodide, were found capable of increasing the ionic conductivity of VE resin an order of magnitude without adversely affecting the resin viscosity, mechanical properties, or reaction kinetics. The most suitable dopant found in this investigation was a tetrabutylammonium acetate (TA) organic salt. TA, at a 0.1 wt% concentration, was shown to have negligible effects on the mechanical properties and reaction kinetics of a curing VE part. TA was found to slightly increase the rate at which viscosity increases, but not to the extent that would hinder resin transfer molding of a doped VE system. This investigation has proven that doping of VE resin with 0.1 wt% TA is a viable means of controlling and tailoring the conductivity of high resistivity resins for the application of direct current (DQ sensing technology.