纤维素浆粕性质对其在NMMO溶液中的溶胀性能的影响

Effect of pulp characteristics on swelling property of cellulose in NMMO solution

将4种聚合度及α-纤维素含量不同的纤维素浆粕在85℃下分别溶解于质量分数为74%,78%,80%的N-甲基吗啉-N-氧化物(NMMO)溶液中,研究了纤维素浆粕性质对其在NMMO溶液中的溶胀性能的影响。结果表明:纤维素浆粕的结晶度越高、聚合度越大、α-纤维素含量越高,溶胀效果越差;在相同实验条件下,浆粕的疏松性对其溶胀效果影响很大,浆粕越疏松,其溶胀效果越好;溶胀过程不会改变纤维素的晶型,但会使纤维素结晶度有所下降;聚合度适中、结晶度较低,疏松的纤维素浆粕适宜作为Lyocell纤维的原料。

Four kinds of cellulose pulps with different polymerization degree andα-cellulose content were separately dissolved in 74%,78%and 80%N-methylmorpholine-N-oxide(NMMO)solution by mass fraction at 85℃.The effect of pulp characteristics on the swelling property of cellulose in NMMO solution was studied.The results showed that the higher the crystallinity,the degree of polymerization andα-cellulose content of cellulose pulp,the poorer the swelling property of cellulose in NMMO solution;the pulp loose gave a great effect on the swelling effect under the same experimental conditions,that is,the looser the pulp,the better swelling effect;the crystal type of cellulose did not change but the crystallinity decreased in swelling process;and the loose cellulose pulp with the moderate polymerization degree and relatively low crystallinity was suitable as the raw material for Lyocell fiber.