Paper number 219

MONITORING THE DURABILITY OF PPS, NYLON, AND PVDF USING IN SITU FDEMS SENSING FOR EXTENDED USE IN THE FIELD

D. Kranbuehl, J. Rogozinski, A. Meyer, C. Higgins, C. Ambler, E. Powell, C. Davis

Department of Chemistry and Applied Science
College of William and Mary, PO Box 8795
Williamsburg, Virginia 23187-8795

Summary

This report describes recent work on the use of dielectric and tensile-torsional measurements to monitor aging in thermoplastics during use in the field. Particular thermoplastics being studied are polyphenyline sulfide, (PPS), graphite tape, along with polyamide-11, (PA-11), and polyvinyl difluoride, (PVDF), which are used for flexible composite pipe to transport oil-gas in an offshore subsea environment. Current life monitoring work focuses on characterizing the chemical and physical processes occurring during aging, using frequency dependent dielectric measurements, FDEMS, to monitor the aging rate and state of the polymer, and integrating the sensor output with a model for predicting the remaining service life and state of the structure. The model predictions are periodically updated through the in situ online sensing measurements. This report will also discuss work on developing a fundamental understanding of the relationship of the sensor measurement of the ionic and dipolar mobility to the macroscopic properties of polymeric materials.

Keywords

ageing, degradation, sensing, durability, dielectric-mechanical-chemical properties, in situ.