Technical parameters of dissolution and separation of cotton stalk cellulose in ionic liquid

As a new green solvent, ionic liquid is a non-derivative solvent of cellulose which can be used to carry out homogeneous reaction. In order to solve the problems of complex cellulose production process and serious pollution, The paper investigated the solubility of cotton stalk cellulose in ionic liquid N-ethyl pyridinium bromide. The structural differences between cotton stalk cellulose and cellulose regenerated from the ionic liquid were investigated using infrared (IR) spectroscopy and chemical analysis. Recovery ratio of ionic liquids was also studied. The results show that cotton stalk cellulose can dissolve in the ionic liquid directly and does not cause derivative reaction of the solute. The optimal conditions of dissolution are that dissolution temperature is 120℃, the separation method is to add water after cooling to room temperature, dissolution time is 30 min and the ratio of material to ionic liquid is 1:2. Ionic liquid can be recycled many times, and activation is not reduced obviously.