Title: Degradation Kinetics of Pultruded E-Glass/Vinylester in Alkaline Media

Author(s): Vistasp M. Karbhari and Wellington Chu

Publication: Materials Journal

Volume: 102

Issue: 1

Appears on pages(s): 34-41

Keywords: alkali; deterioration; fiber-reinforced polymer; glass fiber

DOI: 10.14359/14247

Date: 1/1/2005

Abstract:
Results are presented from a 75-week investigation aimed at characterization of deterioration mechanisms and performance of E-glass/vinylester in an alkaline environment. The material is characterized using dynamic mechanical thermal analysis, fourier-transform infrared spectroscopy, gravimetric moisture uptake, tensile and short-beam-shear tests, and microscopy. Results show a range of deterioration mechanisms initiating with reversible plasticization of the resin and transitioning to irreversible fiber-matrix debonding, hydrolysis, and chain scission of the resin, and pitting and material loss of the fiber. Reconditioning, following periods of immersion, results in some regain in tensile strength over at least half the exposure period, whereas after 15 weeks there is almost no regain in interlaminar shear strength. Predictions of long-term response match fairly closely with experimental results at the 75-week level and show that, under self-similar continuation of deterioration, 26.89% of the original tensile strength and 58.24% of the short-beam-shear strength can be expected to be retained after 50 years.