磷酸酯类离子液体对纤维素溶解性能的研究

采用一步法合成了两种磷酸酯类离子液体:1,3-二甲基咪唑磷酸二甲酯盐(MMIM]DMP)和1-乙基-3-甲基咪唑磷酸二乙酯盐(EMIM]DEP),并比较了它们对纤维素的溶解性能。结果表明,两种离子液体均能在一定条件下溶解纤维素,而EMIM]DEP表现出较优的溶解能力,再生得到纤维素膜;随着溶解温度的升高,溶解时间缩短。采用红外光谱(FT-IR)、热重失重(TGA)分析、X射线衍射(XRD)、扫描电镜(SEM)等对再生前后的纤维素进行了表征。结果表明,未经活化的纤维素可直接溶于离子液体中而不发生其它衍生化反应;溶解再生后的纤维素晶型发生变化;经EMIM]DEP溶解再生后纤维素热稳定性和聚合度下降较小,再生纤维素膜结构致密均一。

Study on Dissolution of Cellulose in Two Phosphate-based Ionic Liquids

Two phosphate-based ionic liquids,DMP and DEP ionic liquids were synthesized by one step method.Dissolution of cellulose in ionic liquid DMP and DEP was compared.It showed that both of them can dissolve cellulose under certain conditions and DEP displayed the better solubility.With the dissolution temperature increased,the dissolution time was greatly reduced.The both original cellulose and rege-nerated cellulose were characterized by Fourier transform infrared spectroscopy(FT-IR),thermogravimetry(TG),X-ray diffraction(XRD) measurements and scanning electron microscopy(SEM).Results showed that the novel system was a good non-derivatizing cellulose solution.The crystal of regenerated cellulose changed,the thermostability and the degree of the polymerization of regenerated cellulose from DEP decreased slightly.The surfaces of regenerated films displayed uniformity,indicating a dense texture.