Study On Green Preparation And Spinnability Of Tea-derived Cellulose

The Agricultural and forestry production in China produces a large amount of biomass solid waste every year,which not only affects the surrounding environment,but also causes a lot of waste of resources.The output of tea and the area of tea garden in our country rank first in the world,but most of the abandoned summer and autumn tea in tea producing areas contain a large amount of cellulose resources which cannot be fully utilized,and the high-value development and utilization of this part of cellulose resources,it can not only reduce the impact on the environment to some extent,but also provide reference for the effective utilization of the waste fiber resources produced by nature and human activities.The waste formed in the processing of tea products,tea dregs and low-grade tea all contain a large number of cellulose resources,which not only have the characteristics of ordinary fibers,what’s more,it also contains rich active ingredients of tea.In this study,tea-derived cellulose was extracted from the waste of the daily pruning and processing of tea trees by secondary chemical cooking,the optimum parameters of each factor in the first cooking and the level range of the orthogonal experiment in the second cooking were studied by single factor experiment.The results showed that the optimum technological parameters for alkali extraction of cellulose were 4%sodium hydroxide at 55°C for 2h.In the second cooking process,the optimum technological parameters of Na OH concentration 10%,extraction temperature 85°C,extraction time 4h,additive concentration 2%,and acid sodium chlorite concentration 9% were obtained,the extraction temperature was 95°C,the extraction time was 3h and the concentration of glacial acetic acid was30 m L/L.the optimum extraction parameters of formic acid method were 88% formic acid,110°C and 5h.The tea-derived cellulose was extracted by the above-mentioned optimal technological parameters and characterized by SEM,FTIR and TGA.The purity and yield of the cellulose extracted by caustic soda method were relatively high,but some of the cellulose had “Peeling reaction” and the ash content was higher than that of the original;the yield of the tea-derived cellulose extracted by acidic sodium chlorite method was low,lignin removal was more effective,but the content of hemicellulose impurities was higher,the content of impurities in tea-derived cellulose extracted by formic acid method was higher,and the yield was similar to that of cellulose extracted by caustic soda method,and its ash content is smaller than the caustic soda method and the original sample.Cellulose solution was prepared by dissolving tea-derived cellulose in N-methylmorpholineN-oxide（NMMO）solvent,and nano-fiber membrane was prepared by electrospinning.The results of SEM,FTIR and contact angle test show that the nano-fiber membrane prepared by celluloseNMMO solution has no fiber orientation and good film-forming property.The cellulose membrane was prepared by adding carboxymethyl chitosan/sodium alginate in cellulose-NMMO solution.The hydrogen bond of cellulose was completely opened and the hydrophilicity was improved,among them,cellulose carboxymethyl chitosan/sodium alginate membrane has the strongest hydrophilicity.