Notin Laure, Viton Christophe, Lucas Jean-Michel, Domard Alain
Société Europlak, 740, av. du 8 Mai 1945, 83130 La Garde, France.
Acta Biomater. 2006 May;2(3):297-311. doi: 10.1016/j.actbio.2005.12.005. Epub 2006 Feb 3.
A pseudo-dry-spinning process of chitosan without any use of organic solvent or cross-linking agent was studied. A highly deacetylated chitosan (degree of acetylation=2.7%) from squid-pens, with a high weight-average molecular weight (M(W)=540,000 g/mol) was used. The polymer was dissolved in an acetic acid aqueous solution in order to obtain a polymer concentration of 2.4% w/w with a stoichiometric protonation of the -NH(2) sites. The coagulation method consisted of subjecting the extruded monofilament to gaseous ammonia. The alkaline coagulation bath classically used in a wet-spinning process was therefore not useful. A second innovation dealt with the absence of any aqueous washing bath after coagulation. The gaseous coagulation was then directly followed by a drying step under hot air. When the chitosan monofilament coagulated in the presence of ammonia gas, ammonium acetate produced with the fiber could be hydrolyzed into acetic acid and ammonia, easily eliminated in their gaseous form during drying. The pseudo-dry-spinning process did not give rise to any strong degradation of polymer chains. After 2 months at ambient atmosphere, chitosan fibers could then be stored without any significant decrease in the M(W), which remained at a rather high value of 350,000 g/mol. The obtained chitosan fibers showed a smooth, regular and uniformly striated surface.
研究了一种不使用任何有机溶剂或交联剂的壳聚糖假干纺工艺。使用了来自鱿鱼笔的高度脱乙酰化壳聚糖（乙酰化度 = 2.7%），其重均分子量较高（M(W)=540,000 g/mol）。将该聚合物溶解在乙酸水溶液中，以获得聚合物浓度为2.4% w/w且 -NH(2)位点进行化学计量质子化的溶液。凝固方法是使挤出的单丝暴露于气态氨中。因此，湿纺工艺中经典使用的碱性凝固浴在此并不适用。第二项创新是凝固后不进行任何水洗浴。气态凝固后直接进行热风干燥步骤。当壳聚糖单丝在氨气存在下凝固时，与纤维一起产生的醋酸铵可水解为醋酸和氨，在干燥过程中以气态形式很容易被除去。假干纺工艺不会导致聚合物链发生任何严重降解。在环境大气中放置2个月后，壳聚糖纤维可以储存，其M(W)没有任何显著降低，仍保持在相当高的350,000 g/mol值。所获得的壳聚糖纤维表面光滑、规则且有均匀的条纹。
