Regenerated bacterial cellulose fibres.

The global shortage of cotton for textile production, forces the exploitation of forests´ lignocellulosic biomass to produce man-made cellulosic fibres (MMCF). This has a considerable environmental impact, pressing the textile industry to search for new sustainable materials and to the development of sustainable recycling processes. Bacterial cellulose (BC), an exopolysaccharide produced by fermentation, could represent such an alternative. In particular, we tested the possibility of improving the mechanical properties of cellulose filaments with a low degree of polymerization (DP) by combining them with high DP from BC, so far exploited to little extent in the textile field. In this work, BC with different degrees of polymerization (DPcuaxam) (BCneat: 927; BCdep:634 and BCblend: 814) were dissolved in N-methylmorpholine-N-oxide (NMMO) and their spinnability was studied. The rheological behaviour of the dopes was assessed and all were found to be spinnable, at suitable concentrations (BCneat:9.0 %; BCdep:12.2 %; BCblend:10.5 %). A continuous spinning was obtained and the resulting filaments offered similar mechanical performance to those of Lyocell. Further, the blending of BC pulps with different DPs (BCblend, obtained by combining BCneat and BCdep) allowed the production of fibres with higher stiffness (breaking tenacity 56.4 CN.tex-1) and lower elongation (8.29 %), as compared to samples with more homogeneous size distribution (neat BC and depolymerized BC).