棉纤维在NMMO溶液中的溶胀与溶解

用不同质量分数的N-甲基吗啉-N-氧化物(NMMO)溶液,在不同的温度和时间条件下,探究棉纤维的溶胀和溶解情况,并利用X射线衍射和红外光谱对纤维素溶胀前后的结构变化进行表征。结果表明:NMMO质量分数低于80%时,棉纤维只溶胀不溶解;在质量分数分别为83%、85%、87%的NMMO溶液中,棉纤维出现溶解现象;随着NMMO质量分数的增大、温度的升高、时间的延长,棉纤维的溶胀程度不断增加。在质量分数为83%的NMMO溶液中,棉纤维先溶胀后溶解;在质量分数为87%的NMMO溶液中,棉纤维不溶胀直接溶解;在质量分数为85%的NMMO溶液中,棉纤维的溶解存在先溶胀后溶解和直接溶解两种形式。质量分数为80%以下的NMMO水溶液处理后的棉纤维,结晶结构和化学结构均没有变化。

Swelling and Dissolution of Cotton Fibers in NMMO Solution

Swelling and dissolution of cotton fiber in different concentration of NMMO solution,temperatureand time were investigated.The changes of structure were characterized by X-ray diffraction and infraredspectrum.The results showed that when the concentration of NMNO was below 80%,the cotton fiber wasswelled without dissolved;when the concentration of NMNO was 83%,85%,87% respectively,the cotton fi-be was dissolved.With the increase of NMMO concentration,temperature and time,the swelling degree ofcotton fiber increased.When the concentration of NMMO was 83%,the cotton fiber was swelled then dis-solved;when the concentration of NMMO was 87%,the cotton fiber was dissolved without swelled;when theconcentration of NMMO was 85%,the cotton fiber was dissolved in two informs.After treated by the concen-tration of NMMO below 80%,the crystalline and chemical structure of the cotton fiber didn't changed.