Title: Advanced Assessment of Resin Integrity in FRP Stack Liners Using Nanoindentation

Authors: Sang Kim

DOI:

Abstract: This study evaluates the condition and performance of fiber-reinforced polymer (FRP) exhaust stack liners used in power plant service, with emphasis on analytical methods for assessing resin degradation. Samples were collected from multiple elevations of a deteriorated liner section in a coal-fired generating station to characterize composition, microstructure, condition, degradation mechanisms, and mechanical properties. Conventional evaluation methods, including visual inspection, microscopy and flexural testing, revealed a multilayered FRP structure with coating failure, discoloration, void formation, layer separation, and progressive loss of strength, with deterioration most pronounced near the base of the stack. To further investigate resin integrity at a finer scale, instrumented nanoindentation was introduced alongside conventional Shore hardness testing. This approach enabled high-resolution measurements of elastic modulus and hardness within resin-rich regions, capturing localized degradation gradients not evident in bulk mechanical testing. Results indicate that failure of the protective coating permitted acidic flue gases and condensates to penetrate the laminate, accelerating resin breakdown and localized mechanical property loss. The combined findings underscore the critical role of protective coating integrity in maintaining FRP liner performance and demonstrate that partial, localized deterioration can significantly affect overall structural behavior. Instrumented nanoindentation was shown to be a powerful diagnostic tool for assessing resin degradation in FRP components exposed to aggressive service environments.

References: 1. ASTM E1131-20, 2000, “Standard Test Method for Compositional Analysis of Thermogravimetry”, ASTM International, West Conshohocken, PA, 2000. DOI: 10.1520/E1131-20, www.astm.org. 2. ASTM D7264/D7264M – 21, 2021, “Standard Test Method for Flexural Properties of Polymer Matrix Composite Materials”, ASTM International, West Conshohocken, PA, 2021. DOI: 10.1520/D7264_D7264M-21, www.astm.org. 3. ASTM D2240-15, 2021, “Standard Test Method for Rubber Property - Durometer Hardness”, ASTM International, West Conshohocken, PA, 2021. DOI: 10.1520/D2240-15R21, www.astm.org

Conference: SAMPE 2026

Publication Date: 2026/04/27

SKU: 38

Pages: 13

Price: $26.00