Method for preparing cellulose with low degree of polymerization and low crystallinity using high-temperature heat treatment

Abstract

The invention relates to a method for preparing cellulose with low degree of polymerization and low crystallinity using high-temperature heat treatment. According to the method, no additional solventor solution is required, the crystalline region and amorphous region structures of the cellulose are directly destroyed by heat treatment at specified temperature and time, the effect of hydrogen bonding on the solubility of the cellulose is reduced, the dissolving activity of the cellulose is increased, and the method has the advantages of low production cost, less pollution, simple process flowand the like, and is beneficial to the regeneration processing production of the cellulose.

Description

technical field [0001] The invention relates to the technical field of cellulose, in particular to a method for preparing cellulose with low polymerization degree and low crystallinity by high-temperature heat treatment. Background technique [0002] Cellulose (Cellulose) is the most widely existing renewable resource in nature. It has the characteristics of abundant sources, good biodegradability and biocompatibility, and easy derivatization. It is expected to become one of the main chemical raw materials in the future. Cellulose has strong intramolecular and intermolecular hydrogen bonds, high degree of orientation and crystallinity, so that it cannot be dissolved in general solvents, and lacks thermoplasticity, making it difficult to form and process. At present, the regenerated cellulose products widely used in the market are mainly prepared by the viscose method, and the viscose method adopts CS 2 Derivatizing cellulose and then regenerating it into products such as ce...

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Problems solved by technology

The preparation cycle of this method is long, the process is more complicated, and the final product needs to be ground and pulverized, and the obtained cellulose has a very low degree of polymerization, which is not suitable for a process that requires relatively high product strength.

[0005] Chinese patent CN104774878A discloses a method for reducing the crystallinity of cellulose. This invention mainly solves the problem of increased crystallinity of cellulose after pretreatment in the hydrothermal treatment process of the production of fuel ethanol from existing lignocellulosic raw materials, which is not conducive to the subsequent fermentation process. problem, the method combines cellulose with Fe 3+ The solution is mixed evenly, placed in a hydrothermal reaction kettle, stirred evenly under a nitrogen atmosphere, a certain pressure and a rotating speed, then heated up and kept warm under a nitrogen atmosphere, a certain pressure and temperature, and finally the reaction kettle is cooled to room temperature in cold water, Open the reaction kettle and filter the obtained solid-liquid mixture with suction, and the obtained solid material is low-crystallinity fiber after washing and drying

[0007] From the above, it can be known that a simple and low-cost production process that can simultaneously reduce the degree of polymerization and crystallinity of cellulose without adding a solvent has not been reported in the prior art.

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