Study On The Dissolution And Ultra-Micronization Of Leather Waste In Ionic Liquid

The desolation and ultra-micronization of the leather waste in [Emim]Br ionic liquid was studied, and the preparation of ligin/collagen fiber composite materials was researched.First of all, the optimum dissolution technological conditions was studied by single factor and orthogonal experiments, which was:mass ratio of leather waste and [Emim]Br ion liquid was 1:20, dissolution temperature was 140 ℃, dissolution time was 60 min. Leather waste dissolving percentage can be stable at around 26.7% under the condition. Contrast the FT-IR figure of leather waste before and after its dissolution, peak at 3406 cm-1 on behalf of the hydrogen bonds between collagen molecule chain was shifted to 3426 cm-1, hydrogen bonds was damaged by [Emim]Br ionic liquid. Contrast the FT-IR figure of leather waste before and after its regeneration, peak at 3406 cm-1 shifted to 3413 cm-1, faint blue shift occured.Secondly, the best process conditions of ultra-micronization were studied by single factor and orthogonal experiments, which was:with liquid paraffin as dispersion medium, the mass ratio of liquid paraffin and [Emim]Br ionic liquid was 8:1, OP-40, K12 and Dowfax 2A1 was compound according to 7:2:1 as dispersants, dispersant dosage was 2%o, dispersion temperature was 80 ℃, setting time was 17h. According to repeated experiment under the best conditions, the average quality of ultra-micronization leather waste on and below 220 nm filter membranes was controlled in 0.2107 g, accounts for about 52.7% of the total quality.Then, the preparation of the lignin/collagen fiber composite materials was researched. The results showed that washing [Emim]Br ionic liquid by suction filter, in a single water consumption was 20 mL, total water consumption was 60 mL, stand time was 60 h, film forming effect of composite materials was good. Research results also showed that the better conditions of preparation of collagen adsorption material by use collagen fiber/lignin composite materials was:the concentration of NaOH was 2.5%, dissolution temperature of 40 ℃, dissolution time was 30min, the proportion of lignin and collagen fiber was 1:4. The adsorption effect to lignin of collagen material in methylene blue solution, alkali lignin and ethanol lignin was studied. The results showed that the decolorization rate to the methylene blue solution was 84.76%, the adsorption rate to alkali lignin was 82.53%, while the ethanol lignin was only 23.99%.Finally, the [Emim]Br ionic liquid for each part of the experiment was recycled. The structure of the ionic liquid remains unchanged after used three or four times, and the recovery rate was over 98%. The [Emim]Br ionic liquid can be reused well.