DMSO对纤维素在咪唑型离子液体中溶解性能的影响

Effect of DMSO Addition on Dissolution of Cellulose in Ionic Liquid

本文通过向传统离子液体中添加助溶剂DMSO来增强离子液体对纤维素的溶解效果。系统研究了DMSO添加量对纤维素溶解性能的影响,结果表明50℃下随着DMSO添加量的增大,纤维素的溶解程度增加,当DMSO添加量为50%时溶解效果最佳。采用电导率测试研究了DMSO与离子液体的作用机理,并通过FT-IR、XRD、TGA、SEM以及力学性能测试等方法对添加不同量DMSO溶剂溶解再生后的纤维素膜进行了分析,结果表明添加DMSO后溶剂仍为纤维素的直接溶剂,溶解再生后纤维素晶型由Ⅰ转变为Ⅱ型,并且随着DMSO添加量的增加,溶剂对纤维素分子链及结晶区的破坏能力增大,从而导致再生纤维素结晶度、抗拉强度及聚合度相对纯离子液体再生的有所降低。

It is reported in this paper that addition of DMSO in an ionic liquid improves the dissolution of cellulose in the ionic liquid.The effect of the mass fraction of DMSO on the solubility of cellulose was investigated.The results showed that dissolution degree of cellulose in the ionic liquid is increased with the addition of DMSO at 50℃.A possible role of the DMSO in the dissolution of cellulose was studied by means of conductivity test.The cellulose films regenerated from different solvents were analyzed by FT-IR,XRD,TGA and mechanics performance testing.The results indicated that the solvents are still non-derivatizing solvents for cellulose,and they make the crystal form of regenerated cellulose transform from typeⅠ to type Ⅱ.Furthermore,the increase in content of DMSO damages crystalline regions,lowers the crystallinity,tensile strength,thermal stability and degree of polymerization of the regenerated cellulose.The photograph and SEM image showed that the regenerated cellulose film was homogeneous and dense.