Cross-linking agents for the protection of lyocell against fibrillation: stability of benzeneacrylamido compounds to high temperature acidic environments

A number of benzeneacrylamido compounds, each with at least one sulphonic acid or carboxylic acid group, have been synthesised and converted to the corresponding methyl ethers. The derivatives were then subjected to high temperature polyester dyeing conditions (130 degrees C) in pH 4.0 buffer solution for 1 h. Derivatives with sulphonic acid groups meta or para to the amide links proved to be hydrolytically stable to the high temperature treatment, whereas derivatives with either an ortho sulphonic acid or carboxylic acid substituent underwent significant amide hydrolysis. This is consistent with previous findings and with a neighbouring group participation mechanism. Accordingly, benzeneacrylamido cross-linking agents for lyocell fibres, designed to be hydrolytically stable to a range of high temperature polyester dyeing conditions appropriate for polyester/lyocell blends, should be devoid of ortho sulphonic acid or carboxylic acid substituents.