Ionic Doping of Low Conductivity Structural Resins for Improved Direct Current Sensing

Abstract

This investigation developed amethodology 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. Anumber 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 themechanical 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 (DC) sensing technology.

Keywords

ionic conductivity flow and cure sensing organic salts vinyl-ester

Get full access to this article

View all access options for this article.

References

1. Walsh, S. M. 1993. “In-Situ Sensor Method and Device,” US Patent No. 5,210,499, May 11.

2. Don, R. C. , K. R. Bernetich , B. K. Fink , M. Louderback , and J. W. Gillespie, Jr. 1998. “Large-Scale Implementation of Flow and Cure Sensing in a Thermoset Resin Infused Composite Structure,” Proceedings of the 43rd International SAMPE Symposium/Exhibition: Materials and Process Affordability—Keys to the Future, SAMPE, Covina, CA.

3. Fink, B. K. , S. M. Walsh , D. C. DeSchepper , J. W. Gillespie, Jr. , R. L. McCullough , R. C. Don , and B. J. Waibel . 1995. “Advances in Resin Transfer Molding Flow Monitoring Using SMARTweave Sensors,” Proceedings of the ASME Materials Division, MD-Vol. 69.2, International Mechanical Engineering Conference and Exposition, 999–1015.

4. Fink, B. K. , S. M. Walsh , D. C. DeSchepper , J. Kleinmeyer , S. Bickerton , and R. C. Don . 1995. “ Development of a Two-Sided Wiring Scheme for Resin Transfer Molding Flow Monitoring Using SMARTweave Sensor,” CCM Technical Report, No. 95-08.

5. Bradley, J. E. , B. K. Fink , and J. W. Gillespie, Jr. , “On-Line Process Monitoring and Analysis of Large Thick-Section Composite Parts Utilizing SMARTweave In-Situ Sensing Technology,” Proceedings of the 43rd International SAMPE Symposium/Exhibition: Materials and Process Affordability—Keys to the Future, SAMPE, Covina, CA, 1998.

6. Schwab, S. D. , R. L. Levy , and G. G. Glover , 1996. “Sensor System for Monitoring Impregnation and Cure During Resin Transfer Molding,” Polymer Composites, 17 2: 312–316.

7. Kleitz, G. F. 1987. Solid State Ionics.22: 295-295.

8. Steele, B. C. H. 1984. Solid State Ionics.12: 391-391.

9. Burgess, J. 1988. Ions in Solution: Basic Principles of Chemical Interactions.Halsted Press, New York.

10.

10. Brill, R. P. , R. L. McCullough , and G. R. Palmese . 1996. Proceedings of 11th Technical Conference of ASC.