Composition of plant raw materials

There are many kinds of plant raw materials, but their basic composition has little difference, mainly composed of sugar and non-sugar.

. Different plant raw materials have different contents of each component. The following briefly introduces the three main components of plant raw materials:

Cellulose ether, lignin and hemicellulose.

1.3 Basic composition of plant raw materials

1.3.1.1 Cellulose

Cellulose is a macromolecular polysaccharide composed of D-glucose with β-1,4 glycosidic bonds. It is the oldest and most abundant on earth.

Natural polymer. Its chemical structure is usually represented by Haworth structural formula and chair conformation structural formula, where n is the degree of polysaccharide polymerization.

Cellulose Carbohydrate Xylan

arabinoxylan

glucuronide xylan

glucuronide arabinoxylan

glucomannan

Galactoglucomannan

arabinogalactan

Starch, pectin and other soluble sugars

non-carbohydrate components

lignin

Extract Lipids, Lignols, Nitrogenous Compounds, Inorganic Compounds

Hemicellulose Polyhexopolypentose Polymannose Polygalactose

Terpenes, resin acids, fatty acids, sterols, aromatic compounds, tannins

plant material

1.4 Chemical structure of cellulose

1.3.1.2 Lignin

The basic unit of lignin is phenylpropane, which is then connected by C-C bonds and ether bonds.

type polymer. In the plant structure, the intercellular layer contains the most lignin,

The intracellular content decreased, but the lignin content increased in the inner layer of the secondary wall. As intercellular substance, lignin and hemifibrils

Together they fill in between the fine fibers of the cell wall, thereby strengthening the cell wall of the plant tissue.

1.5 Lignin structural monomers, in order: p-hydroxyphenylpropane, guaiacyl propane, syringyl propane and coniferyl alcohol

1.3.1.3 Hemicellulose

Unlike lignin, hemicellulose is a heteropolymer composed of several different kinds of monosaccharides. According to these

The types of sugars and the presence or absence of acyl groups can be divided into glucomannan, arabinosyl (4-O-methylglucuronic acid)-xylan,

Galactosyl glucomannan, 4-O-methylglucuronic acid xylan, arabinosyl galactan, etc. in,

Fifty percent of the wood tissue is xylan, which is on the surface of cellulose microfibrils and interconnected with the fibers.

They form a network of cells that are more firmly connected to each other.

1.4 The research purpose, significance and main content of this topic

1.4.1 Purpose and significance of the research

The purpose of this research is to select three representative species through the analysis of the components of some plant raw materials.

Cellulose is extracted from plant material. Select the appropriate etherifying agent, and use the extracted cellulose to replace the cotton to be etherified and modified to prepare fiber.

Vitamin ether. The prepared cellulose ether was applied to reactive dye printing, and finally the printing effects were compared to find out more

Cellulose ethers for reactive dye printing pastes.

First of all, the research of this topic has solved the problem of reuse and environmental pollution of plant raw material waste to a certain extent.

At the same time, a new way is added to the source of cellulose. Secondly, the less toxic sodium chloroacetate and 2-chloroethanol are used as etherifying agents,

Instead of highly toxic chloroacetic acid, cellulose ether was prepared and applied to cotton fabric reactive dye printing paste, and sodium alginate

The research on substitutes has a certain degree of guidance, and also has great practical significance and reference value.

Fiber Wall Lignin Dissolved Lignin Macromolecules Cellulose

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1.4.2 Research content

1.4.2.1 Extraction of cellulose from plant raw materials

Firstly, the components of plant raw materials are measured and analyzed, and three representative plant raw materials are selected to extract fiber.

Vitamins. Then, the process of extracting cellulose was optimized by the comprehensive treatment of alkali and acid. Finally, UV

Absorption spectroscopy, FTIR and XRD were used to correlate the products.

1.4.2.2 Preparation of cellulose ethers

Using pine wood cellulose as raw material, it was pretreated with concentrated alkali, and then the orthogonal experiment and single factor experiment were used,

The preparation processes of CMC, HEC and HECMC were optimized respectively.

The prepared cellulose ethers were characterized by FTIR, H-NMR and XRD.

1.4.2.3 Application of cellulose ether paste

Three kinds of cellulose ethers and sodium alginate were used as the original pastes, and the paste formation rate, water holding capacity and chemical compatibility of the original pastes were tested.

The basic properties of the four original pastes were compared with respect to properties and storage stability.

Using three kinds of cellulose ethers and sodium alginate as the original paste, configure printing color paste, carry out reactive dye printing, pass the test table

Comparison of three cellulose ethers and

Printing properties of sodium alginate.

1.4.3 Innovation points of research

(1) Turning waste into treasure, extracting high-purity cellulose from plant waste, which adds to the source of cellulose

A new way, and at the same time, to a certain extent, it solves the problem of reuse of waste plant raw materials and environmental pollution; and improves the fiber

Extraction method.

(2) Screening and degree of substitution of cellulose etherifying agents, commonly used etherifying agents such as chloroacetic acid (highly toxic), ethylene oxide (causing

Cancer), etc. are more harmful to the human body and the environment. In this paper, the more environmentally friendly sodium chloroacetate and 2-chloroethanol are used as etherification agents.

Instead of chloroacetic acid and ethylene oxide, cellulose ethers are prepared. (3) The obtained cellulose ether is applied to cotton fabric reactive dye printing, which provides a certain basis for the research of sodium alginate substitutes.

refer to.