The N-acylation of chitosan fibre and the N-deacetylation of chitin fibre and chitin¯cellulose blended fibre at a solid state

Not only the filament surface of chitosan fibre but also its inside was N-acylated at a solid state by treatment with a series of carboxylic anhydrides in methanol at room temperature, and novel N-acylchitosan fibres (d.s. 0.8¯1.1 for NAc) were obtained. Their filament tenacity and elongation values were little influenced by the N-acylation. Each of chitin fibre and chitin¯cellulose blended fibre was treated with aq. 40% NaOH at 95¯100°C for 4 h at a suspension state, and a chitosan fibre and a novel cellulose¯chitosan blended fibre were obtained. The relative hydrolysis rate of N-acetyl, N-propionyl and N-butyrylchitosan fibres by an egg-white lysozyme were 1.0:0.3:0.0 at a suspension state. A SEM observation revealed a scaly pattern on the surface of the N-octanoylchitosan filament.