A kind of preparation method of cotton cellulose nanofibril film

Abstract

The invention discloses a method for preparing a cotton cellulose nanofibril film. Cotton is used as a raw material, and the raw material is made into pulp through processes such as acidolysis and hydrothermal reaction. After the fiber is refined and beaten, the hemicellulose and lignin in the cotton cell wall are degraded and modified through the joint action of various degrading enzymes, and then the cellulose fiber is carboxylated by using chloroacetic acid, etc., which can effectively pass the stripping process. The obtained cellulose nanofibrils are treated with grinding and homogenization in the process of microfibrillation. Through multiple grindings, the microfibrils can be fluffed and swollen to form water balls full of water, and then stretched and expanded by homogenization, and finally become The cellulose nanofibrils are finally dehydrated to form a thin film. The preparation process of the present invention is scientific, the process parameters are precise, the reaction conditions are mild, and the cost is significantly reduced, which is suitable for commercial and industrial production requirements.

Description

technical field [0001] The invention belongs to the technical field of polymer materials, and in particular relates to a method for preparing a cotton cellulose nanofibril film. Background technique [0002] With the continuous development of human society, people's demand for energy and materials is increasing day by day. The extensive use of traditional fossil energy has led to serious environmental problems, and the research on renewable resources has become particularly important. Cellulose is the most abundant natural polymer compound on earth, with good biocompatibility, biodegradability and biosynthesis. With the rapid development of material science, research on cellulose-based materials has gradually become a hot topic. The application of nanotechnology has greatly expanded the application fields of cellulose-based materials. Cellulose nanofibrils (CNF) have the characteristics of high strength, low density and low thermal expansion coefficient due to their high ...

AI Technical Summary

Problems solved by technology

TEMPO oxidation is a good method for surface modification of natural cellulose. Natural fibers introduce carboxyl and aldehyde functional groups in a mild aqueous environment. Fibers prepared by this method have high requirements for the selection of raw materials. The morphology of biomass cellulose nanofibrils does not change, and the oxidation only occurs on the surface of the microfibrils and makes them negatively charged, so that repulsion occurs between the fibrils, thereby reducing the hydrogen bond force between the fibrils, Eventually microfibrillation occurs, this method has mild conditions and effectively removes lignin, but its production cost is too high

[0004] At the same time, CNF nanofibers mainly rely on high-speed shear force and friction to swell and separate cellulose molecules into microfibril bundles with a diameter of nanometers. However, the current high-speed shear process usually requires a high-speed motor to provide a power source. , so each homogenization process consumes a large amount of electrical energy, which has also become a limiting factor for the commercial production of nanofibrils