Spinning Properties Of Lignocellulose/chitosan In 1-butyl-3-methylimidazolium Chloride

With the rising price of petroleum and the depletion of one-time resources in the future,the use of natural polymer materials instead of petrochemical products to prepare fibers has attracted great attention of scientific workers.Cellulose and chitosan have attracted much attention because of their excellent properties.Cellulose/chitosan blend fiber has broad application prospects in biomedical and other fields.However,there are some problems in the preparation of cellulose/chitosan blend fibers,such as poor compatibility,poor mechanical properties and poor antibacterial properties.It is of great theoretical and practical significance to study the solubility and spinning properties of cellulose/chitosan in ionic liquids,and to prepare blended fibers with the advantages of cellulose fiber and chitosan fiber,so as to make full use of natural resources and improve the differential ratio of fiber raw materials in China’s textile industry.In this paper,the dissolution behavior of cellulose in 1-butyl-3-methylimidazolium chloride([BMIM]Cl)was studied by orthogonal design.The cellulose was characterized by polarizing microscope,scanning electron microscope,X-ray diffraction,degree of polymerization,infrared spectrum and thermogravimetric analysis.The results showed that the cellulose dissolved in [BMIM]Cl was directly dissolved,and the thermal stability of regenerated cellulose decreased,and the crystal form changed from cellulose I to cellulose II.The degradation degree of lignocellulose/[BMIM]Cl blends can be reduced by ultrasonic treatment.The results showed that the optimal dissolution conditions of lignocellulose in [BMIM]Cl were as follows: stirring rate 100 r/min,dissolution temperature 100℃,ultrasonic treatment for1 h.Response surface methodology was used to explore the optimal dry jet wet spinning process of cellulose/chitosan spinning solution.Taking the breaking strength of regenerated fiber as the response value,the quadratic polynomial regression model was fitted.Through variance analysis and significance test,it was found that the interaction of draw ratio,air gap length,spinning solution temperature,draw ratio and air gap length had significant influence on the breaking strength of regenerated fiber.Based on the analysis results of response surface graph,the optimal dry jet wet spinning process of cellulose/chitosan spinning solution is as follows: draw ratio is 2.7,air gap is 2.0 cm,spinning solution temperature is 80℃.Finally,cellulose/chitosan blend fibers with different ratios were prepared and characterized by scanning electron microscopy,X-ray diffraction,infrared spectroscopy,thermogravimetric analysis and antibacterial properties.The SEM results showed that the two components in the blend fiber were well mixed and dense.With the increase of the ratio of chitosan,the surface defects of the blend fiber began to appear,and the defects gradually became serious,and the thermal stability decreased.The antibacterial properties of the blend fiber to Escherichia coli and Staphylococcus aureus increased,but the breaking strength and elongation at break decreased.The results of FTIR and XRD show that the two components have good compatibility.When the content of chitosan was 5%,the breaking strength and elongation at break of the blend fiber were1.46 c N/dtex and 16.31%,respectively,and the antibacterial rates against Escherichia coli and Staphylococcus aureus were 94.66% and 96.68%.