新型功能化离子液体[HeEIM]Cl的合成及其对棉纤维的溶解性能

Synthesis of Novel and Functionalized Ionie Liquid [HeEIM]Cl and Its Solubility for Cotton Fibre

合成了离子液体氯化1-(2-羟乙基)-3-乙基-咪唑([HeEIM]Cl),并利用FTIR和1HNMR对其化学结构进行了表征.考察了NaOH、微波和高压等处理方式对棉纤维的结晶度、聚合度(DP)和溶解率的影响.研究了不同的溶解温度在微波加热和传统加热条件下对棉纤维的溶解率和再生纤维素的聚合度的影响.利用FTIR,XRD,TGA和SEM等方法分别对溶解后得到的再生纤维素的化学结构、结晶度变化、热稳定性和表观形貌进行了分析.结果表明,合成的离子液体对棉纤维表现出很好的溶解能力,且在溶解和再生过程中未发生化学变化.棉纤维在高压条件下经质量分数为30%的NaOH预处理后,溶解性能最佳.微波加热法的溶解效果远远优于传统加热法,且随着温度的升高,溶解率逐渐增大.溶解后得到的再生纤维素的结晶度变小,聚合度下降,热稳定性降低.

In this paper, ionic liquid of 1 - （2-hydroxylethyl） -3-ethyl imidazolium chloride （ [ HeEIM ] Cl） was synthesized, and the chemical structure of [ HeEIM ] Cl was confirmed by FTIR and ^1H NMR. The influence of NaOH, microwave and high-pressure on crystallinity, degree of polymerization（ DP）, solubility of cotton fibre were studied. The effects of different temperatures on dissolution rate of cotton fibre and DP for the regenerated cellulose were investigated on the conditions of microwave heating and traditional heating respectively. The chemical structure, change of crystallinity, thermostability and appearance of the regenerated cellulose were analyzed by FTIR, XRD, TGA and SEM respectively. The results show that the ionic liquid exhibited a good ability of dissolution for cotton fibre, and during the dissolution and coagulation processes of the celloluse, no chemical reaction occurred. The solubility was the best when the cotton fibre was pretreated with 30% （mass fraction） NaOH on the high pressure condition. The solubility by microwave heating was far superior to traditional heating method, and with the dissolution temperatures elevation, the dissolution rate increased gradually. The crystallinity of the regenerated cellulose was lower than that of original cellulose, the DP of the regenerated cellulose declined and thermostability dropped.