A method of cellulose electrospinning

Abstract

The invention relates to the field of natural high polymer material preparation, in particular to a method for lowering the viscosity of a cellulose electrostatic spinning solution and promoting spinning. The method includes the following steps: 1) immersing cellulose in a solvent so as to allow the cellulose to swell partly, wherein the mass fraction of the solvent in the swollen cellulose is 10%-80%, and the solvent is methyl alcohol and / or ethyl alcohol; 2) dissolving lithium chloride in dimethylacetamide, and adding linoleic acid trehalose monoester to acquire a mixture; 3) adding the swollen cellulose acquired from the step 1) to the mixture acquired from the step 2), and acquiring the cellulose solution; and 4) performing electrostatic spinning by using the cellulose solution acquired from the step 3). The linoleic acid trehalose monoester is dispersed between cellulose lamellas, can lower the entanglement effect of cellulose molecular chains, can suppress hydrogen-bond interaction while the cellulose lamellas are regenerated, and can promote stretching and fiber forming of the cellulose in electrostatic spinning.

Description

technical field [0001] The invention relates to the field of preparation of natural polymer materials, in particular to a cellulose electrospinning method. Background technique [0002] Cellulose not only has the characteristics of wide sources, non-toxic, and degradable, but also the ultrafine cellulose fibers prepared by electrospinning have controllable size, high specific surface area, and high aspect ratio (diameter 20-50 μm, length > 100 μm) , low density and low thermal expansion coefficient and other properties. Ultrafine cellulose fibers can be widely used in filter adsorption, paper packaging and various composite materials. The core issue in the application of cellulose electrospinning is the preparation of the spinning solution. Solvents suitable for cellulose dissolution have been reported in the literature, such as N-methylmorpholine oxide / water, alkali / urea / water, ionic liquids, etc., but cellulose is still difficult to electrospin to prepare ultrafine fi...

AI Technical Summary

Problems solved by technology

[0005] Cellulose swelling is a pretreatment process for cellulose dissolution. Previous swelling methods: heat treatment in ethylenediamine solution, soaking in NaOH solution, high-temperature DMAc treatment, and then dissolved in a high-temperature DMAc / LiCL system. These methods can change the cellulose Water retention, specific surface area, crystallinity, can even change the cellulose to form grafts on the C6 bond, such as amidation, and high temperature swelling treatment studies have shown that thermal swelling at a temperature exceeding 120°C will lead to deamination cracking of DMAc, and the ammonia produced Degrades cellulose, which is easy to oxidize and turn yellow; another common method is solvent exchange, cellulose is swelled in water, then rinsed and soaked repeatedly with ethanol or acetone, and then rinsed and soaked with DMAc solvent again. After solvent exchange, Then the cellulose is removed from the DMAc solvent, the solvent exchange method has a better effect, but the efficiency is too low, the crystallinity change and the fiber chemical change are very subtle, and the cellulose concentration after dissolution is low (1-5%wt / v), and the viscosity is low. High, difficult to electrospin, on the other hand, DMAc / LiCl solution is a very sensitive salt-organic solvent system, LiCl has strong hygroscopicity, and the complex salt structure formed with DMAc is very easy to dissociate in the solution system, strong polarity The amine-based solution will lead to cellulose gel, dissolution and destruction, making the free volume of cellulose in DMAc / LiCl solution smaller, the movement of molecular chains is difficult, the viscosity is high, and the morphology of fiber spinning is uneven

Images