This paper examines the leaching patterns of pyruvic acid, and relates this to similar patterns of oxalic, glyoxylic and malonic acids in a further attempt to clarify the mechanism of the corrosion process. It appears that these acids selectively leach boron to a greater extent than other cations, and as boron is part of the E-glass matrix rather than just an interstitial ion, this would explain the means by which these relatively weak acids are able to corrode the glass fibres. It is well known that oxalic acid forms strong complexes with boron, and it is likely that other dicarboxylic acids or carboxylic acids with appropriate placed ligand groups will do likewise. This work represents a study of the rate of strength loss and the rate of leaching of cations from E-glass fibres with particular emphasis on boron.
