Protection of lyocell against fibrillation. Part 3: Investigation of the durability of crosslinks formed with 4,6-(p-β-sulphatoethylsulphonyl)-anilino-1,3,5-triazin-2(1H)-one on lyocell fibre

摘要

Application of 4,6-(p-β-sulphatoethylsulphonyl)-anilino-1,3,5-triazin-2(1H)-one (Hydroxy-XLC) to lyocell fibre produced two types of crosslinking, one essentially permanent and the other transitory, in the presence of weak alkali. Permanent or stable crosslinking arose from covalent bonding between the fibre and vinyl sulphone reactive groups. The transitory or unstable crosslinking was due to two agent molecules forming an intermolecular ether linkage, followed by crosslinking via the residual vinyl sulphone reactive groups. On subsequent mild alkali treatment, the ether bond was cleaved, resulting in a loss of wet abrasion resistance (Nass-Scheuer-Festigkeit, NSF), without any significant loss of agent from the fibre. Further treatment with mild alkali partially restored the NSF value. The formation of ethers is a general reaction of vinyl sulphones in alkaline medium, and for Hydroxy-XLC, this side reaction exerts a negative influence on the compound's suitability as a crosslinking agent.