Preparation of cellulose. Cellulose formula

All our lives we are surrounded by a huge number of objects - cardboard boxes, offset paper, plastic bags, viscose clothing, bamboo towels and much more. But few people know that cellulose is actively used in their production. What is this truly magical substance, without which almost no modern industrial enterprise? In this article we will talk about the properties of cellulose, its use in various fields, as well as what it is extracted from, and what it is chemical formula. Let's start, perhaps, from the beginning.

Substance detection

The cellulose formula was discovered French chemist Anselm Payen during experiments on separating wood into its components. Having treated it with nitric acid, the scientist discovered that during chemical reaction a fibrous substance similar to cotton is formed. After careful analysis of the resulting material, Payen obtained the chemical formula of cellulose - C 6 H 10 O 5. A description of the process was published in 1838, and the substance received its scientific name in 1839.

Gifts of nature

It is now known for certain that almost all soft parts of plants and animals contain some amount of cellulose. For example, plants need this substance for normal growth and development, or more precisely, for the creation of the membranes of newly formed cells. In composition it belongs to polysaccharides.

In industry, as a rule, natural cellulose is extracted from coniferous and deciduous trees - dry wood contains up to 60% of this substance, as well as by processing cotton waste, which contains about 90% cellulose.

It is known that if wood is heated in a vacuum, that is, without air access, it will thermal decomposition cellulose, resulting in the formation of acetone, methyl alcohol, water, acetic acid and charcoal.

Despite the rich flora of the planet, there are no longer enough forests to produce the amount of chemical fibers required for industry - the use of cellulose is too extensive. Therefore, it is increasingly extracted from straw, reeds, corn stalks, bamboo and reeds.

Synthetic cellulose is produced from coal, oil, natural gas and shale using various technological processes.

From the forest to the workshops

Let's look at the extraction of technical cellulose from wood - this is a complex, interesting and lengthy process. First of all, wood is brought to production, cut into large fragments and the bark is removed.

The cleaned bars are then processed into chips and sorted, after which they are boiled in lye. The resulting cellulose is separated from the alkali, then dried, cut and packaged for shipment.

Chemistry and physics

What chemical and physical secrets are hidden in the properties of cellulose besides the fact that it is a polysaccharide? First of all, this substance white. It ignites easily and burns well. It dissolves in complex compounds of water with hydroxides of certain metals (copper, nickel), with amines, as well as in sulfuric and orthophosphoric acids, a concentrated solution of zinc chloride.

Cellulose does not dissolve in available household solvents and ordinary water. This happens because the long thread-like molecules of this substance are connected in peculiar bundles and are located parallel to each other. In addition, this entire “structure” is strengthened by hydrogen bonds, which is why molecules of a weak solvent or water simply cannot penetrate inside and destroy this strong plexus.

The thinnest threads, the length of which ranges from 3 to 35 millimeters, connected into bundles - this is how you can schematically represent the structure of cellulose. Long fibers are used in the textile industry, short fibers are used in the production of, for example, paper and cardboard.

Cellulose does not melt or turn into steam, but it begins to decompose when heated above 150 degrees Celsius, releasing low molecular weight compounds - hydrogen, methane and carbon monoxide (carbon monoxide). At temperatures of 350 o C and above, cellulose becomes charred.

Change for the better

Like this in chemical symbols describes cellulose, the structural formula of which clearly shows a long-chain polymer molecule consisting of repeating glucosidic residues. Note the "n" indicating a large number of them.

By the way, the formula for cellulose, derived by Anselm Payen, has undergone some changes. In 1934, the English organic chemist, laureate Nobel Prize Walter Norman Haworth studied the properties of starch, lactose and other sugars, including cellulose. Having discovered the ability of this substance to hydrolyze, he made his own adjustments to Payen’s research, and the cellulose formula was supplemented with the value “n”, indicating the presence of glycosidic residues. On this moment it looks like this: (C 5 H 10 O 5) n.

Cellulose ethers

It is important that cellulose molecules contain hydroxyl groups, which can be alkylated and acylated, forming various esters. This is another one of the most important properties that cellulose has. Structural formula different connections might look like this:

Cellulose ethers are either simple or complex. Simple ones are methyl-, hydroxypropyl-, carboxymethyl-, ethyl-, methylhydroxypropyl- and cyanoethylcellulose. Complex ones are nitrates, sulfates and cellulose acetates, as well as acetopropionates, acetylphthalylcellulose and acetobutyrates. All these ethers are produced in almost all countries of the world in hundreds of thousands of tons per year.

From photographic film to toothpaste

What are they for? As a rule, cellulose ethers are widely used for the production of artificial fibers, various plastics, all kinds of films (including photographic), varnishes, paints, and are also used in military industry for the production of solid rocket fuel, smokeless powder and explosives.

In addition, cellulose ethers are part of plaster and gypsum-cement mixtures, fabric dyes, toothpastes, various adhesives, synthetic detergents, perfumes and cosmetics. In a word, if the cellulose formula had not been discovered back in 1838, modern people would not have many of the benefits of civilization.

Almost twins

Few of them ordinary people knows that cellulose has a kind of twin. The formula of cellulose and starch is identical, but these two are completely different substances. What's the difference? Despite the fact that both of these substances are natural polymers, the degree of polymerization of starch is much less than that of cellulose. And if you delve further and compare the structures of these substances, you will find that cellulose macromolecules are arranged linearly and only in one direction, thus forming fibers, while starch microparticles look slightly different.

Areas of application

One of the best visual examples of practically pure cellulose is ordinary medical cotton wool. As you know, it is obtained from carefully purified cotton.

The second, no less used cellulose product is paper. In fact, it is a thin layer of cellulose fibers, carefully pressed and glued together.

In addition, viscose fabric is produced from cellulose, which, under the skillful hands of craftsmen, magically turns into beautiful clothes, upholstery for upholstered furniture and various decorative draperies. Viscose is also used for the manufacture of technical belts, filters and tire cords.

Let's not forget about cellophane, which is made from viscose. It’s hard to imagine supermarkets, shops, packaging departments of post offices without it. Cellophane is everywhere: candy is wrapped in it, cereals are packed in it, bakery products, as well as tablets, tights and any equipment, ranging from mobile phone and ending with the remote control remote control for TV.

In addition, pure microcrystalline cellulose is included in weight loss tablets. Once in the stomach, they swell and create a feeling of fullness. The amount of food consumed per day is significantly reduced, and accordingly, weight falls.

As you can see, the discovery of cellulose produced a real revolution not only in chemical industry, but also in medicine.

Structure.

The molecular formula of cellulose is (-C 6 H 10 O 5 -) n, like that of starch. Cellulose is also a natural polymer. Its macromolecule consists of many residues of glucose molecules. The question may arise: why are starch and cellulose substances with the same molecular formula– have different properties?

When considering synthetic polymers, we have already found out that their properties depend on the number of elementary units and their structure. The same situation applies to natural polymers. It turns out that the degree of polymerization of cellulose is much greater than that of starch. In addition, by comparing the structures of these natural polymers, it was established that cellulose macromolecules, unlike starch, consist of residues of the b-glucose molecule and have only a linear structure. Cellulose macromolecules are located in one direction and form fibers (flax, cotton, hemp).

Each residue of a glucose molecule contains three hydroxyl groups.

Physical properties .

Cellulose is a fibrous substance. It does not melt and does not go into a vapor state: when heated to approximately 350 o C, cellulose decomposes - it chars. Cellulose is insoluble in water or most other inorganic and organic solvents.

The inability of cellulose to dissolve in water is an unexpected property for a substance containing three hydroxyl groups for every six carbon atoms. It is well known that polyhydroxyl compounds are easily soluble in water. The insolubility of cellulose is explained by the fact that its fibers are like “bundles” of parallel thread-like molecules connected by many hydrogen bonds, which are formed as a result of the interaction of hydroxyl groups. The solvent cannot penetrate inside such a “bundle”, and therefore the molecules do not separate from each other.

The solvent for cellulose is Schweitzer's reagent - a solution of copper (II) hydroxide with ammonia, with which it simultaneously interacts. Concentrated acids(sulfuric, phosphoric) and a concentrated solution of zinc chloride also dissolve cellulose, but in this case its partial decomposition (hydrolysis) occurs, accompanied by a decrease in molecular weight.

Chemical properties .

The chemical properties of cellulose are determined primarily by the presence of hydroxyl groups. By acting with metallic sodium, it is possible to obtain cellulose alkoxide n. Under the influence of concentrated aqueous solutions alkalis, the so-called mercerization occurs - partial formation of cellulose alcoholates, leading to swelling of the fiber and increasing its susceptibility to dyes. As a result of oxidation, a certain number of carbonyl and carboxyl groups appear in the cellulose macromolecule. Under the influence of strong oxidizing agents, the macromolecule disintegrates. The hydroxyl groups of cellulose are capable of alkylation and acylation, giving ethers and esters.

One of the most characteristic properties cellulose - the ability to undergo hydrolysis in the presence of acids to form glucose. Similar to starch, cellulose hydrolysis occurs in stages. In summary, this process can be depicted as follows:

(C 6 H 10 O 5) n + nH 2 O H2SO4_ nC6H12O6

Since cellulose molecules contain hydroxyl groups, it is characterized by esterification reactions. Of them practical significance have reactions of cellulose with nitric acid and acetic anhydride.

When cellulose reacts with nitric acid in the presence of concentrated sulfuric acid, depending on the conditions, dinitrocellulose and trinitrocellulose are formed, which are esters:

When cellulose reacts with acetic anhydride (in the presence of acetic and sulfuric acids), triacetylcellulose or diacetylcellulose is obtained:

The pulp burns. This produces carbon monoxide (IV) and water.

When wood is heated without access to air, cellulose and other substances decompose. This produces charcoal, methane, methyl alcohol, acetic acid, acetone and other products.

Receipt.

An example of almost pure cellulose is cotton wool obtained from ginned cotton. The bulk of cellulose is isolated from wood, in which it is contained along with other substances. The most common method of producing cellulose in our country is the so-called sulfite method. According to this method, crushed wood in the presence of a solution of calcium hydrosulfite Ca(HSO 3) 2 or sodium hydrosulfite NaHSO 3 is heated in autoclaves at a pressure of 0.5–0.6 MPa and a temperature of 150 o C. In this case, all other substances are destroyed, and cellulose is released comparatively pure form. It is washed with water, dried and sent for further processing, for the most part for paper production.

Application.

Cellulose has been used by humans since very ancient times. At first, wood was used as a fuel and construction material; then cotton, flax and other fibers began to be used as textile raw materials. The first industrial methods of chemical wood processing arose in connection with the development of the paper industry.

Paper is a thin layer of fiber fibers, compressed and glued to create mechanical strength, a smooth surface, and to prevent ink from bleeding. Initially, to make paper, plant materials were used, from which it was possible to obtain the necessary fibers purely mechanically, rice stalks (the so-called rice paper), cotton, and worn-out fabrics were also used. However, with the development of printing listed sources There were not enough raw materials to meet the growing demand for paper. Especially a lot of paper is consumed for printing newspapers, and the issue of quality (whiteness, strength, durability) for newsprint paper does not matter. Knowing that wood consists of approximately 50% fiber, they began to add ground wood to the paper pulp. Such paper is fragile and quickly turns yellow (especially in the light).

To improve the quality of wood additives to paper pulp, various ways chemical processing of wood, making it possible to obtain from it more or less pure cellulose, freed from accompanying substances - lignin, resins and others. Several methods have been proposed for the isolation of cellulose, of which we will consider the sulfite method.

According to the sulfite method, crushed wood is “cooked” under pressure with calcium hydrosulfite. In this case, the accompanying substances dissolve, and the cellulose freed from impurities is separated by filtration. The resulting sulfite liquors are waste in paper production. However, due to the fact that they contain, along with other substances, monosaccharides capable of fermentation, they are used as raw materials for the production ethyl alcohol(so-called hydrolytic alcohol).

Cellulose is used not only as a raw material in paper production, but is also used for further chemical processing. Highest value have cellulose ethers and esters. Thus, when cellulose is treated with a mixture of nitric and sulfuric acids, cellulose nitrates are obtained. All of them are flammable and explosive. Maximum number nitric acid residues that can be introduced into cellulose are equal to three for each glucose unit:

N HNO3_ n

The product of complete esterification - cellulose trinitrate (trinitrocellulose) - must contain 14.1% nitrogen in accordance with the formula. In practice, a product is obtained with a slightly lower nitrogen content (12.5/13.5%), known in the art as pyroxelin. When treated with ether, pyroxylin gelatinizes; after the solvent evaporates, a compact mass remains. Finely chopped pieces of this mass are smokeless powder.

Nitration products containing about 10% nitrogen correspond in composition to cellulose dinitrate: in technology, such a product is known as colloxylin. When exposed to a mixture of alcohol and ether, a viscous solution is formed, the so-called collodion, used in medicine. If you add camphor to such a solution (0.4 parts camphor per 1 part colloxylin) and evaporate the solvent, you will be left with a transparent flexible film - celluloid. Historically, this is the first famous type plastics. Since the last century, celluloid has been widely used as a convenient thermoplastic material for the production of many products (toys, haberdashery, etc.). The use of celluloid in the production of film and nitro varnishes is especially important. A serious disadvantage of this material is its flammability, so celluloid is now increasingly being replaced by other materials, in particular cellulose acetates.

Everyday objects that have become familiar to us and are found everywhere in our Everyday life, it would be impossible to imagine without using the products organic chemistry. Long before Anselm Pay, as a result of which he was able to discover and describe a polysaccharide in 1838, which received “cellulose” (a derivative of the French cellulose and the Latin cellula, which means “cell, cell”), the property of this substance was actively used in the production of the most irreplaceable things.

Expanding knowledge about cellulose has led to the emergence of a wide variety of things made from it. Paper of various types, cardboard, parts made of plastic and artificial viscose, copper-ammonia), polymer films, enamels and varnishes, detergents, food additives (E460) and even smokeless powder are products of the production and processing of cellulose.

In its pure form, cellulose is white solid with quite attractive properties, exhibits high resistance to various chemical and physical influences.

Nature has chosen cellulose (fiber) as its main building material. IN flora it forms the basis for trees and other higher plants. In nature, cellulose is found in its purest form in the hairs of cotton seeds.

Unique properties of this substance are determined by its original structure. The cellulose formula has general entry(C6 H10 O5)n from which we see a pronounced polymer structure. The β-glucose residue, which is repeated a huge number of times and has a more expanded form as -[C6 H7 O2 (OH)3]-, is combined into a long linear molecule.

The molecular formula of cellulose determines its unique Chemical properties withstand the effects aggressive environments. Cellulose is also highly resistant to heat; even at 200 degrees Celsius, the substance retains its structure and does not collapse. Self-ignition occurs at a temperature of 420°C.

Cellulose is no less attractive for its physical properties. cellulose in the form of long threads containing from 300 to 10,000 glucose residues without side branches largely determines the high stability of this substance. The glucose formula shows how many give cellulose fibers not only great mechanical strength, but also high elasticity. The result of analytical processing of the set chemical experiments and research was the creation of a model of the cellulose macromolecule. It is a rigid helix with a pitch of 2-3 elementary units, which is stabilized by intramolecular hydrogen bonds.

It is not the formula of cellulose, but the degree of its polymerization that is the main characteristic for many substances. So in unprocessed cotton the number of glucoside residues reaches 2500-3000, in purified cotton - from 900 to 1000, purified wood pulp has an indicator of 800-1000, in regenerative cellulose their number is reduced to 200-400, and in industrial cellulose acetate it ranges from 150 up to 270 “links” in a molecule.

The product used to obtain cellulose is mainly wood. Basic technological process production involves cooking wood chips with various chemical reagents, followed by cleaning, drying and cutting the finished product.

Subsequent processing of cellulose makes it possible to obtain a variety of materials with specified physical and chemical properties, allowing the production of the most various products, without which life modern man it is hard to imagine. The unique formula of cellulose, adjusted by chemical and physical processing, became the basis for the production of materials that have no analogues in nature, which allowed them to be widely used in the chemical industry, medicine and other branches of human activity.

Cellulose is natural polymer glucose (namely, beta-glucose residues) plant origin with a linear molecular structure. Cellulose is also called fiber in another way. This polymer contains more than fifty percent of the carbon found in plants. Cellulose ranks first among organic compounds on our planet.

Pure cellulose is cotton fibers (up to ninety-eight percent) or flax fibers (up to eighty-five percent). Wood contains up to fifty percent cellulose, and straw contains thirty percent cellulose. There is a lot of it in hemp.

Cellulose is white. Sulfuric acid It turns it blue, and iodine turns it brown. Cellulose is hard and fibrous, tasteless and odorless, does not collapse at a temperature of two hundred degrees Celsius, but ignites at a temperature of two hundred seventy-five degrees Celsius (that is, it is a flammable substance), and when heated to three hundred sixty degrees Celsius, it chars. It cannot be dissolved in water, but can be dissolved in a solution of ammonia and copper hydroxide. Fiber is a very strong and elastic material.

The importance of cellulose for living organisms

Cellulose is a polysaccharide carbohydrate.

In a living organism, the functions of carbohydrates are as follows:

1. The function of structure and support, since carbohydrates take part in the construction of supporting structures, and cellulose is main component structures of plant cell walls.
2. Protective function characteristic of plants (thorns or thorns). Such formations on plants consist of the walls of dead plant cells.
3. Plastic function (another name is anabolic function), since carbohydrates are components of complex molecular structures.
4. The function of providing energy, since carbohydrates are an energy source for living organisms.
5. Storage function, since living organisms store carbohydrates in their tissues as nutrients.
6. Osmotic function, since carbohydrates take part in regulating osmotic pressure inside a living organism (for example, blood contains from one hundred milligrams to one hundred and ten milligrams of glucose, and blood osmotic pressure depends on the concentration of this carbohydrate in the blood). Osmosis transport delivers nutrients in tall tree trunks, since capillary transport is ineffective in this case.
7. The function of receptors, since some carbohydrates are part of the receptive part of cell receptors (molecules on the cell surface or molecules that are dissolved in cell cytoplasm). The receptor reacts in a special way to connection with a certain chemical molecule, which transmits an external signal, and transmits this signal into the cell itself.

The biological role of cellulose is:

1. Fiber is key structural part cell membrane plants. Formed as a result of photosynthesis. Plant cellulose is food for herbivores (for example, ruminants); in their bodies, fiber is broken down using the enzyme cellulase. It is quite rare, so cellulose in its pure form is not consumed in human food.
2. Fiber in food gives a person a feeling of fullness and improves the mobility (peristalsis) of his intestines. Cellulose is capable of binding liquid (up to zero point four grams of liquid per gram of cellulose). In the large intestine it is metabolized by bacteria. Fiber is welded without the participation of oxygen (there is only one anaerobic process in the body). The result of digestion is the formation of intestinal gases and flying fatty acids. Large quantity These acids are absorbed by the blood and used as energy for the body. And the amount of acids that are not absorbed and intestinal gases increase the volume of feces and accelerate its entry into the rectum. Also, the energy of these acids is used to increase the amount of beneficial microflora in the large intestine and support its life there. When the amount of dietary fiber in food increases, the amount of beneficial nutrients also increases. intestinal bacteria the synthesis of vitamin substances improves.
3. If you add thirty to forty-five grams of bran (contains fiber) made from wheat to food, then feces increase from seventy-nine grams to two hundred and twenty-eight grams per day, and the period of their movement is reduced from fifty-eight hours to forty hours. When fiber is added to food regularly, stool becomes softer, which helps prevent constipation and hemorrhoids.
4. When there is a lot of fiber in food (for example, bran), then the body healthy person, and the body of a patient with type 1 diabetes becomes more resistant to glucose.
5. Fiber, like a brush, removes dirty deposits from the intestinal walls and absorbs toxic substances, takes cholesterol and removes it all from the body naturally. Doctors have concluded that people who eat rye bread and bran are less likely to suffer from colon cancer.

The most fiber is found in bran from wheat and rye, in bread made from coarsely ground flour, in bread made from proteins and bran, in dried fruits, carrots, cereals, and beets.

Applications of cellulose

People are already using cellulose for a long time. First of all, wood material was used as fuel and boards for construction. Then cotton, flax and hemp fibers were used to make various fabrics. For the first time in industry, chemical processing of wood material began to be practiced due to the development of the production of paper products.

Currently, cellulose is used in various industrial areas. And it is for industrial needs that it is obtained mainly from wood raw materials. Cellulose is used in the production of pulp and paper products, in the production of various fabrics, in medicine, in the production of varnishes, in the production of organic glass and in other areas of industry.

Let's consider its application in more detail

Silk acetate is obtained from cellulose and its esters, unnatural fibers and a film of cellulose acetate, which does not burn, are made. Smokeless gunpowder is made from pyroxylin. Cellulose is used to make thick medical film (collodion) and celluloid (plastic) for toys, film and photographic film. They make threads, ropes, cotton wool, different kinds cardboard, building material for shipbuilding and house construction. They also get glucose (for medical purposes) and ethyl alcohol. Cellulose is used both as a raw material and as a substance for chemical processing.

A lot of glucose is needed to make paper. Paper is a thin fibrous layer of cellulose that has been sized and pressed using special equipment to produce a thin, dense, smooth surface of the paper product (the ink should not bleed over it). At first, only material of plant origin was used to create paper; the necessary fibers were extracted from it mechanically (rice stalks, cotton, rags).

But book printing developed at a very fast pace, newspapers also began to be published, so the paper produced in this way was no longer enough. People found out that wood contains a lot of fiber, so they began to add ground wood raw materials to the plant mass from which paper was made. But this paper was quickly torn and turned yellow within a very long time. a short time, especially when exposed to light for a long time.

Therefore, they began to develop different methods wood material processing chemicals, which make it possible to isolate from it purified various impurities cellulose

To obtain cellulose, wood chips are boiled in a solution of reagents (acid or alkali) for a long time, then the resulting liquid is purified. This is how pure cellulose is produced.

Acid reagents include sulfurous acid; it is used to produce cellulose from wood with a small amount of resin.

Alkaline reagents include:

1. soda reagents ensure the production of cellulose from hardwoods and annuals (such cellulose is quite expensive);
2. sulfate reagents, of which the most common is sodium sulfate (the basis for the production of white liquor, and it is already used as a reagent for the production of cellulose from any plants).

After all production stages, the paper is used for the production of packaging, book and stationery products.

From all of the above, we can conclude that cellulose (fiber) has an important cleansing and healing value for the human intestines, and is also used in many areas of industry.

A complex carbohydrate from the group of polysaccharides that is part of the cell wall of plants is called cellulose or fiber. The substance was discovered in 1838 by the French chemist Anselme Payen. The formula of cellulose is (C 6 H 10 O 5) n.

Structure

Despite the common characteristics, cellulose differs from another plant polysaccharide - starch. The cellulose molecule is a long, exclusively unbranched chain of saccharides. Unlike starch, which consists of α-glucose residues, it includes many β-glucose residues linked to each other.

Due to the dense linear structure of the molecules, they form fibers.

Rice. 1. The structure of the cellulose molecule.

Cellulose has greater degree polymerization than starch.

Receipt

In industrial conditions, cellulose is boiled down from wood (chips). For this purpose, acidic or alkaline reagents are used. For example, sodium hydrosulfite, sodium hydroxide, lye.

As a result of cooking, cellulose with an admixture is formed organic compounds. To clean it, use an alkali solution.

Physical properties

Fiber is a tasteless, white, solid fibrous substance. Cellulose is poorly soluble in water and organic solvents. Dissolves in Schweitzer's reagent - ammonia solution copper(II) hydroxide.

Basic physical properties:

• destroyed at 200°C;
• burns at 275°C;
• self-ignites at 420°C;
• melts at 467°C.

In nature, cellulose is found in plants. It is formed during photosynthesis and performs a structural function in plants. Is a food additive E460.

Rice. 2. Plant cell wall.

Chemical properties

Due to the presence of three hydroxyl groups in one saccharide, fiber exhibits the properties polyhydric alcohols and is capable of entering into esterification reactions to form esters. When decomposed without oxygen, it decomposes into charcoal, water and volatile organic compounds.

The main chemical properties of fiber are presented in the table.

Reaction	Description	The equation
Hydrolysis	Occurs when heated in an acidic environment with the formation of glucose	(C 6 H 10 O 5) n + nH 2 O (t°, H 2 SO 4) → nC 6 H 12 O 6
With acetic anhydride	Formation of triacetylcellulose in the presence of sulfuric and acetic acids	(C 6 H 10 O 5) n + 3nCH 3 COOH (H 2 SO 4) → (C 6 H 7 O 2 (OCOCH 3) 3) n + 3nH 2 O
Nitration	Reacts with concentrated nitric acid at ordinary temperature. An ester is formed - cellulose trinitrate or pyroxylin, used to make smokeless powder	(C 6 H 10 O 5) n + nHNO 3 (H 2 SO 4) → n
	Complete oxidation occurs to carbon dioxide and water	(C 6 H 10 O 5) n + 6nO 2 (t°) → 6nCO 2 + 5nH 2 O

Rice. 3. Pyroxylin.

Cellulose is mainly used for making paper, as well as for the production of esters, alcohols, and glucose.

What have we learned?

Cellulose or fiber is a polymer from the carbohydrate class, consisting of β-glucose residues. Included in plant cell walls. It is a white, tasteless substance that forms fibers that are poorly soluble in water and organic solvents. Cellulose is isolated from wood by cooking. The compound undergoes esterification and hydrolysis reactions and can decompose in the absence of air. At complete decomposition forms water and carbon dioxide.