无机盐/离子液体对再生纤维素结构与性能的影响

合成了一种离子液体1-烯丙基-3-甲基咪唑亚磷酸甲酯盐([Amim][(MeO)PHO_2]),这种离子液体能很好地溶解纤维素,并加入与其阴离子结构类似的无机盐亚磷酸氢二钠(Na_2PHO_3)组成复合溶解体系。文中研究了离子液体和复合体系对纤维素结构与性能的影响,通过对原生和再生纤维素展开红外光谱、热重分析、X射线衍射及聚合度的测试表征,结果显示再生纤维素没有发生衍生化,但热稳定性和结晶度及聚合度均比原生纤维素低,且随着复合溶解体系中Na_2PHO_3含量的增大,从中再生出来的纤维素的聚合度越高、热降解温度越高、结晶度越低。这种结果可能是由于无机盐的加入降低了离子液体对纤维素的酸降解而导致的。

Effects of Inorganic Salts/Ionic Liquids on the Structure and Properties of Regenerated Cellulose

In this paper,a new type of ionic liquid 1-allyl-3-methylimidazolylphosphite salt ([Amim] [(MeO) PHO2]) was synthesized,it can well dissolve cellulose.And an inorganic salt disodium hydrogen phosphite (Na2PHO3) was added into [Amim] [(MeO)PHO2],which formed composite solvents for cellulose.The influences of the ionic liquid and composite solvents on the structure of regenerated cellulose were investigated.The untreated cellulose (original cellulose) and regenerated celluloses were characterized with WAXD,FT-IR,TGA,and degree of polymerization(DP) was also measured.The results show that the crystallinity,the rapid decomposition temperature and degree of polymerization of regenerated celluloses are lower than those of the original cellulose,but the solvents act as non-derivatizing solvents for original cellulose.Moreover,the content of Na2PHO3 in ionic liquid increases,the crystallinity of regenerated cellulose decreases,but rapid decomposition temperatures and DP of regenerated celluloses increase.These results might be resulted from that the addition of Na2PHO3 to [Amim] [(MeO)PHO2] inhibit the cellulose hydrolysis in ionic liquid during dissolution and regeneration.