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The reaction equation for the polycondensation of aminocaproic acid. Macromolecular compounds




Task 433
What compounds are called amines? Draw a scheme for the polycondensation of adipic acid and hexamethylenediamine. Name the resulting polymer.
Solution:
Amines are called derivatives of hydrocarbons, formed by substitution in the last hydrogen atoms for groups -NH 2 , -NHR or -NR" :

Depending on the number of hydrogen atoms at the nitrogen atom, substituted by radicals ( R ), amines are called primary, secondary or tertiary.

Group -NH2 , which is part of the primary amines, is called the amino group. group of atoms >NH in secondary amines is called imino group.

Polycondensation scheme adipic acid and hexamethylenediamine:

Anid (nylon) is the product of polycondensation of adipic acid and hexamethylenediamine.

Task 442
What compounds are called amino acids? Write the formula for the simplest amino acid. Draw a scheme for the polycondensation of aminocaproic acid. What is the resulting polymer called?
Solution:
Amino acids compounds are called, the molecule of which contains both amine(-NH2) and carboxyl groups(-COOH). Their simplest representative is aminoacetic acid (glycine): NH2-CH2-COOH.

Aminocaproic acid polycondensation scheme:

The polycondensation product of aminocaproic acid is called capron (perlon). From capron get fibers that are stronger than natural fibers. These fibers are used in the production of clothing, car and aircraft tire cords, for the manufacture of durable and non-rotting fishing nets and gear, rope products, etc.

This is a crystalline substance with Tmelt = 68.5 - 690 C. Let's dissolve well in water, alcohol, ether and other organic solvents. Aqueous solutions of acids cause hydrolysis to ε - ami-

nocaproic acid. When heated to 230 - 2600 C in the presence of small amounts of water, alcohol, amines, organic acids, it polymerizes to form a polyamide resin.

ly. It is a product of large-scale production.

ω-Dodecalactam (laurinlactam) is obtained by a multi-stage synthesis from 1,3-butadiene.

3CH2

Laurin lactam is a crystalline substance with Tmelt = 153 - 1540 C, readily soluble in alcohol, benzene, acetone, poorly in water. When heated, it polymerizes into polyamide, however,

polymerization proceeds worse than that of ε-caprolactam. (Lauric or dodecanoic acid - CH3 (CH2) 10 COOH.)

4.2. Methods for obtaining polyamides Polyamides are usually referred to the group of polycondensation polymers, i.e. polymers,

emitted as a result of polycondensation reactions. Such an assignment is not very correct,

since polymers of this type can be obtained both by polycondensation and polymerization

zation of monomers. Polycondensation produces polyamides from ω-aminocarboxylic acids

(or their esters), as well as from dicarboxylic acids (or their esters) and diamines. The main polymerization methods are hydrolytic and catalytic polymerization of lacta-

mov ω-amino acids. The choice of method is determined by the possibilities of the raw material base and the requirements -

mi to the properties of the corresponding polyamide.

In industry, polyamides are obtained in four main ways:

Heteropolycondensation of dicarboxylic acids or their esters with organic diamines

n HOOCRCOOH + n H2 NR"NH2

N H2 O

- heteropolycondensation of dicarboxylic acid chlorides with organic dia-

- homopolycondensationω-aminocarboxylic acids (amino acids) or their esters;

N H2 O

- polymerization of amino acid lactams.

catalyst

n (CH2 )n

HN(CH2)n CO

4.3. Polyamide labeling The polyamide labeling system is based on the production method and chemical

structure. A number of polyamides, especially aromatic ones, have their own names, established

provided by manufacturing firms.

For aliphatic polyamides after the word "polyamide" ("nylon" in foreign literature)

round) followed by one or two numbers separated by a comma (or dot). If the polyamide is synthesized from one monomer (amino acid or lactam), one number is put,

corresponding to the number of carbon atoms in the monomer. For example, polyamide obtained from

ε-caprolactam or from ε-aminocaproic acid, referred to as "polyamide 6"; a polymer from aminoenanthic acid - "polyamide 7", a polymer from aminoundecanoic acid -

"polyamide 11". In the technical literature, the word "polyamide" is often replaced by the abbreviation "PA" or the letter "P". Then the above designations are presented as "PA-6", "PA-11", "P-7". The composition of two numbers separated by a comma indicates that the polyamide is obtained by polycondensation of a diamine with a dicarboxylic acid or its derivatives.

The number (number) before the decimal point indicates the number of carbon atoms in the diamine; the number (number) after the decimal point is the number of carbon atoms in the used acid or its derivative. For example, "Polyamide 6,6" is derived from hexamethylenediamine and adipic acid; "Polyamide 6.10" -

from hexamethylenediamine and sebacic acid. Note that the comma (or period)

separating two numbers may be missing. So, the State Standard 10539 - 87

it is prescribed to designate the polyamide obtained from hexamethylenediamine and sebacic acid in poly, as in the amides "Polyamide obtained610". from aliphatic amines and aromatic acids, a linear structural element is indicated by a number showing the number of carbon atoms in a molecule

kule, and the link of acids is indicated by the initial letter of their names. For example, polyamide

derived from hexamethylenediamine and tere-phthalic acid, referred to as "Polyamide

The names of polyamide copolymers are made up of the names of individual polymers with an indication

percentage composition in brackets (in the literature there is a use of a hyphen instead of brackets). The first indicated is the polyamide, which is more in the copolymer. For example, name-

“Polyamide 6.10 / 6.6 (65:35)” or “Polyamide 6.10 / 6.6 - 65/35” mean that the copolymer co-

made of 65% polyamide 6.10 and 35% polyamide 6.6. In some cases, simplified notation is used. For example, the entry P-AK-93/7 means that the copolymer is prepared from 93% AG salt and 7% ω-caprolactam (here "A" denotes AG salt, "K" - caprolactam).

In addition to these designations standardized in Russia, in the technical and reference literature, there may be proper names of individual types and brands introduced by firms.

lyamides. For example, "Technamid", "Zytel-1147" and others.

4.4. Production of aliphatic polyamides Of the many polyamides synthesized to date, the most practical

of interest are:

Polyamide 6 (poly-ε-caproamide, polycaproamide, capron, nylon resin, nylon-6,

caprolon B, caprolite),

Polyamide 12 (poly-ω-dodecanamide),

Polyamide 6.6 (polyhexamethylene adipamide, anide, nylon 6.6),

Polyamide 6.8 (polyhexamethylenesuberinamide),

Polyamide 6.10 (polyhexamethylene sebacinamide),

Polyamides 6 and 12 are obtained in the art by polymerization of the corresponding lactams. Os-

tal polyamides are formed during the polycondensation of hexamethylenediamine and dibasic acids

4.4.1. Polymerization of lactams Polyamide 6 and polyamide 12 are predominantly obtained in this way.

4.4.1.1. Polyamide 6

Polyamide 6 or polycaproamide is obtained by polymerization of ε-caprolactam in

the absence of hydrolytic agents or catalysts that promote the opening of the lactam ring. The process of polymerization under the action of water is called hydrolytic polymerization.

tion. Catalytic (anionic or cationic) polymerization of ε-caprolactam proceeds in the presence of alkaline or acid catalysts. The main amount of PA-6 is obtained by hydrolytic polymerization of caprolactam.

Hydrolytic polymerization of ε-caprolactam flows under the action of water, sol-

ditch acids, salts or other compounds that cause hydrolysis of the lactam cycle. Education-

The reduction of polyamide proceeds in two stages. The chemistry of the process can be represented by the scheme:

H2 N(CH2 )5COOH

HN(CH2 )5 CO

The first stage of the process, hydrolysis of caprolactam to aminocaproic acid, is the slowest stage of the process, which limits its overall rate. Therefore, in

In water, the polymerization of caprolactam is carried out in the presence of catalysts. These are most often the aminocaproic acid itself or the salt of AG (hexamethylene adipate, the salt of adi-

pinic acid and hexamethylenediamine - HOOC (CH2)4 COOH H2 N(CH2)6 NH2), in which the reagents are in strictly equimolecular ratios.

The macromolecule of the resulting polyamide contains free terminal carboxyl and amino groups, which is why it is prone to destructive reactions and further polycondensation.

tion when heated during processing. To obtain a more stable product, these groups can be blocked by introducing monofunctional substances into the reaction mass - alcohols, acids or amines. Such compounds, called stabilizers or regulator-

viscosities, react with end groups and thereby stabilize the polymer, limiting its ability to enter into further reactions. This ensures the possibility of

obtain a polymer with a given molecular weight and viscosity by changing the amount of stabilizer

congestion. Acetic and benzoic acids are often used as a stabilizer.

Hydrolytic polymerization is a reversible process and the equilibrium state depends on temperature. When carrying out the reaction in the temperature range of 230 - 2600 C, the content of mo-

number and oligomers in the resulting polyamide is 8 - 10%. At such temperatures, all reagents and polyamide can be actively oxidized by atmospheric oxygen. Therefore, the process is carried out in an inert atmosphere of dry nitrogen with a high degree of purification.

The polymerization process can be carried out according to periodic or continuous schemes using equipment of various designs. On fig. Figure 3 shows a scheme for the production of PA 6 by a continuous method in a column-type reactor. The technological process of folding

It consists of the stages of preparation of raw materials, polymerization of ε-caprolactam, cooling of the polymer, its grinding, washing and drying.

Preparation of raw materials consists in melting caprolactam at 90 - 1000 C in a separate apparatus

rate 3 with stirring. In apparatus 6, a 50% aqueous solution of AG salt is prepared. Prepare-

The prepared liquids are continuously supplied by dosing pumps 1 and 4 through filters 2 and 5

in the upper part of the reactor 7 (column about 6 m high with horizontal perforated

mi metal partitions that contribute to the turbulence of the flow of reagents when they move from top to bottom). The reactor is heated through jacket sections with dinil (a eutectic mixture of diphenyl and diphenyl ether). The temperature in the middle part of the column is about 2500 C,

in the lower - up to 2700 C. The pressure in the column (1.5 - 2.5 MPa) is provided by the supply of nitrogen and pa-

ramie of the resulting water.

Polymerization begins immediately after mixing the components. released during the reaction

tion and the water introduced with the AG salt evaporates. Its vapors, rising along the column, contribute to turbulence and mixing of the reaction mass and entrain caprolactam vapors with them.

Upon exiting the column, the vapor mixture sequentially enters reflux condensers 8

and 9. In the first, caprolactam is condensed, returning to the column. Condensed-

In the second, water vapor is removed for cleaning. The monomer conversion in the column is about 90%.

Caprolactam

for cleaning

Rice. 3. Scheme for the production of polyamide 6 (polycaproamide) by a continuous method:

1, 4 - dosing pumps; 2, 5 - filters; 3 - caprolactam melter; 6 - apparatus for dissolving AG salt; 7 - column-reactor; 8, 9, - refrigerators; 10 - cutting machine; 11 - washer-extractor; 12 - filter; 13 - vacuum dryer; 14 - rotating watering drum.

The resulting molten polymer is squeezed out through a slotted die into the co-

the lower part of the column in the form of a tape on the cold surface of a rotating

precise water of the watering drum 14, is cooled and, with the help of guide and pull rolls, enters the cutting machine 10 for grinding.

extractor 11. The content of low molecular weight compounds after washing is less than

1.5%. The washed crumb is separated from the water on the filter 12 and dried in a vacuum dryer

13 at 125 - 1300 C up to a moisture content of not more than 0.2%.

Anionic polymerizationε-caprolactam can be carried out in solution or melt mo-

numbers at temperatures below the melting point of the polymer.

catalyst

n (CH2 )5

HN(CH2 )5 CO

Polymerization is carried out in the presence of a catalytic system consisting of a mixture of

talizator and activator. Alkali metals and their hydroxides can serve as catalysts.

carbonates, other compounds. In technology, mainly sodium salt ε is used - capro-

lactam formed by the interaction of sodium with lactam.

(CH2)5

1/2 H2

N-Na+

This salt easily reacts with lactam to form an N-acyl derivative, which is added

connects to lactam, giving rise to a polyamide chain and remaining at its end until complete

monomer consumption.

(CH2)5

(CH2)5

(CH2)5

N-Na+

N-CO-(CH2)5 - NH

Activators (cocatalysts) help speed up the reaction. In their quality

N-acyl derivatives of lactam or compounds capable of acylating lactam are used

there under polymerization conditions (carboxylic acid anhydrides, esters, isocyanates, etc.). Under

under the influence of such a system, the polymerization of ε-caprolactam proceeds without an induction period

at atmospheric pressure and ends at 140 -

1800 C for 1 - 1.5 hours with a monomer conversion of 97 - 99%.

Caprolactam

Such "soft" conditions and the speed of polymerization

allow it to be carried out not in reactors, but in forms,

having the configuration and dimensions of future products.

Another advantage of anionic polymerization is

the possibility of obtaining polyamides with uniformly distributed

caprolactam

twisted spherulite structure, without shrinkage shells

wines, pores, cracks and other defects.

The method of anionic polymerization of ε-caprolactam in

melt in the presence of sodium salt of ε-caprolactam

and activator was called "high-speed polymer-

zation”, and the resulting polymer is named after

In a heating cabinet

spilled or caprolon B. It is also used on-

caprolite production:

1 - dosing pump; 2 - reactor

title "polyamide block" Assignment of own

production of sodium salt of caprolactam; 3-

filter; 4 - melter; 5 - mixer capro

the name of the poly-ε-

lactam with N-acetylcaprolactam; 6 - before-

zirovochny pump; 7 - mixer; 8 - shape

caproamide is explained by the fact that caprolon B, having the same chemical structure as poly-

amide 6, markedly differs from it in properties. It exhibits (Table 5) higher strength

ness, hardness, heat resistance, has less water absorption, etc.

This is explained, in

slightly larger molecular weight of caprolite, and secondly, more ordered

structure. Obtaining caprolon B includes (Fig. 4)

stages of preparation of raw materials, mixed

components and polymerization.

At the stage of preparation of raw materials, caprolactam is melted and

thoroughly dried under negative pressure in a nitrogen atmosphere in a container

type with stirrer 4.

Half of this melt after filtration is mixed in the appa-

with the calculated amount of metallic sodium for the preparation of sodium salt

ε-caprolactam, and the other half - in apparatus 5 is mixed with a cocatalyst (N - ace-

tilcaprolactam). Both melts (solutions) with a temperature of 135 - 140 0 C are dosed by pump-

mi 1 and 6 in the required proportions into a quick mixer 7, from where the mixture enters the casting molds, the capacity of which can reach 0.4 - 0.6 m3. The filled molds are installed for 1.0 - 1.5 hours in heating cabinets for polymerization with a gradual increase

temperature from 140 to 1800 C. Then the molds with the polymer are slowly cooled to room temperature.

temperature and polymer castings are removed from them. In washing off the monomer, it is necessary -

there is no interest here, since its content does not exceed 1.5–2.5%.

High-speed polymerization of ε-caprolactam is used to obtain large-sized and thick-walled or non-standard finished products, as well as castings, products from which are prepared by mechanical processing.

4.4.1.2. Polyamide 12

Polyamide 12 (poly-ω-dodecanamide or nylon 12) is obtained in industry by methods

hydrolytic and anionic polymerization of ω-dodecalactam.

N H2 O

Hydrolytic polymerization is carried out in the presence of water and acid (adipic,

orthophosphoric). The technology for obtaining nylon 12 by this method is similar to the technology for the synthesis of polyamide 6. The properties of polyamide 12 are shown in table 5.

The anionic polymerization of ω-dodecalactam is also similar to that of ε-caprolactam.

At lower temperatures, a polymer is formed with a higher molecular weight, a more uniformly developed spherulitic structure, and, as a result, with increased physical

mechanical properties.

4.4.2. Polycondensation of hexamethylenediamine and dicarboxylic acids Polyamides from dicarboxylic acids and diamines or from amino acids are obtained by the method

equilibrium polycondensation. For the synthesis of a polymer with a high molecular weight, it is necessary

dimo fulfill several main conditions. One of them is due to the reversibility of polycondensation reactions. Because of this, the formation of a sufficiently high molecular weight polymer

is possible only with the timely and complete removal of water, which is achieved by carrying out

process in vacuum or with continuous current through the reaction mass of dry inert gas.

In addition, it should be taken into account that as the reaction proceeds, the concentrations of reactants and the rate of the process decrease. A typical way to increase the rate of reactions is to increase the temperature. However, above 3000 C, polyamides begin to noticeably decompose.

swear. Therefore, in order to achieve sufficient conversion, it is necessary to increase the duration

the contact strength of the reagents. Thus, the molecular weight of the resulting polyamides can be controlled during their formation by the duration of the process.

In addition to temperature and time factors, to obtain a high molecular weight

Liamide requires strict equimolecularity of the reagents. An excess of one of them, even within 1%, leads to the formation of polymer chains, at the ends of which there will be

identical functional groups of the excess reagent. With an excess of diamine, the end groups will be NH2 groups, and with an excess of acid, COOH groups. This will stop the chain propagation reaction. Equimolecularity is achieved by using

lycondensation not of the acids and diamines themselves, but of their acid salts. The preparation of such salts is

It is an independent stage in the processes of polyamide synthesis by polycondensation. Used

ion for the polycondensation of salts has a number of advantages: salts are non-toxic, easily crystalline

are lysed, practically do not change, unlike diamines, properties during long-term storage

nii, do not require special storage conditions.

Ensuring the equimolecularity of the reagents should theoretically lead to

the formation of a polymer with an infinitely large molecular weight. However, in industrial practice, due to the inevitable loss of part of the reagents and the passage of side reactions, in which

functional groups can enter, the molecular weight of polymers is in the range of 10,000 - 50,000.

4.4.2.1. Polyamide 6.6

Polyamide 6.6 (polyhexamethylene adipamide, P-66, nylon 6.6, anide) is formed during poly-

condensation of hexamethylenediamine and adipic acid.

HN(CH) NHCO(CH) CO

N H2 O

.... .... ..........

... .

. . ... .. . ... .. .... ..

hot... .. .. ...... ..... . .... .............

. .. ................................ .

..... ..

...... .

..... ....

cold

Polyamide

Fig.5. Scheme for the production of polyhexamethylenediadimamide (polyamide 6.6):

1 - centrifuge; 2 - apparatus for separating salt from a solution; 3 - apparatus for obtaining salt; 4 - autoclave reactor; 5 - refrigerator; 6 - condensate collector; 7 - cutting machine; 8 - dryer; 9 - cooling bath

The first stage of the process is the synthesis of a salt of adipic acid and hexamethylenediami-

on (AG salts). A salt solution is formed in a heated apparatus 3 by mixing 20% ​​me-

tanol solution of adipic acid with 50 - 60% solution of hexamethylenediamine in methanol. In apparatus 2, when the mass is cooled, the AG salt, which is poorly soluble in methanol, is released from the solution. Its crystals are separated from the mother liquid in a centrifuge 1, dried and used

used for polycondensation. Salt - white crystalline powder with Tmelt = 190 - 1910 C,

easily soluble in water, stable when stored dry and in the form of aqueous solutions.

The process of synthesizing polyamide 6,6 from AG salt is not much different from the process of polymerization

ε-caprolactam. The most significant feature is the elevated temperature of the polycone

densations. The optimum reaction rate is reached at 270 - 2800 C. In this case, the reaction proceeds almost to the end, and upon reaching equilibrium, a polymer is formed containing less than 1% of monomers and low molecular weight compounds. The molecular weight distribution is rather narrow. The reason for the absence of significant polydispersity is the side de-

structural processes taking place under the influence of temperature and low molecular weight fractions. First of all, high-molecular fractions are subjected to destruction. For more-

more active limitation of their presence in the commercial polymer, they are added to the reaction mass -

all monofunctional compounds capable of reacting with terminal groups of polyamino-

Yes. As in the synthesis of polyamide 6, such stabilizer compounds (viscosity regulators)

bones) can be acetic, benzoic acid. These compounds not only limit the molecular

the molecular mass of the polymer during its formation, but also contribute to the constancy of the viscosity of the

polymer melt during its processing, i.e. upon remelting, which may cause further polycondensation.

Polycondensation is carried out in an autoclave at a pressure of 1.5 - 1.9 MPa in a nitrogen atmosphere.

Autoclave 4 is loaded with AG salt, the addition of acetic acid (0.1 - 0.2 mol per mol of salt) and

the apparatus through the shirt is heated with dinil to 2200 C. Further, for 1.5 - 2 hours, the dark

The temperature gradually rises to 270 - 2800 C. Then the pressure decreases to atmospheric pressure and after a short exposure rises again. Such pressure changes are repeated

a few times. With a decrease in pressure, the water formed during polycondensation boils

melts and its vapors additionally mix the polymer melt. The water vapor leaving the autoclave is condensed in the refrigerator 5, collected in the collector 6 and discharged into the purification systems.

sewage drains. At the end of the process (6 - 8 hours), the remaining water is removed under vacuum,

and the polyamide melt from the apparatus through the spinneret is squeezed out in the form of a tape into the bath 9 with

4.4.2.2. Polyamides 6.8 and 6.10

These polyamides are obtained by polycondensation of hexamethylenediamine and the corresponding ki-

slot (suberic and sebacic) using technologies similar to the production technology of

diamide 6.6.

Acids and diamine are introduced into the reaction in the form of their salts.

Of these polyamides, only polyamide 610 is of practical interest so far,

since the production of suberic acid is limited by its complexity.

The properties of polyamides 6.8 and 6.10 are shown in table 5.

Mixed polyamides are produced in a similar way when various components are introduced into the polycondensation, for example, salts of AG and caprolactam, salts of AG, SG and caprolac-

4.4.3. Polycondensation of diamines and dicarboxylic acid chlorides

This method has not been widely used in the industry for aliphatic polyamides due to the increased cost of carboxylic acid chlorides. Nonetheless,

it is the only one for the synthesis of most aromatic polyamides, in particular phenylone and Kevlar.

4.5. Properties and applications of aliphatic polyamides Aliphatic polyamides are hard, horn-like products from white to light cream.

movable color, melting in a narrow temperature range (table 5). Narrow intervals

melting point values ​​indicate a low polydispersity and a high concentration

Tractions in polymers of the crystalline phase. Its content can reach 60 - 80% and depends

sieves on the structure of macromolecules. Regular alifati-

cal homopolyamides, a distinctive feature of which is the content in the macro-

molecule of radicals of only one acid and one diamine. These are, for example, polyamide 6,

polyamide 6.6, polyamide 6.10. The degree of crystallinity of the material in products is affected by the conditions

depending on its processing, heat treatment mode, moisture content and special additives. Ste-

the stump of crystallinity of mixed (obtained from two or more monomers) polyamides is less. They are less durable, but have increased elasticity, transparent.

The high melting points of polyamides are explained by strong hydrogen bonds between macromolecules. The number of these bonds directly depends on the number of amide groups in the macromolecule and, therefore, is inversely related to the number of methylene groups. Hydrogen bonds determine to a large extent all other properties. From-

here: the ratio of methylene and amide groups affects both solubility and water resistance

bone, and on physical and mechanical, and on other indicators.

HOOC–CH 2 –NH 2 + HOOC–CH–NH 2 HOOC–CH 2 –NH–CO–CH–NH 2

CH 3 -H 2 O CH 3

glycine alanine glycylalanine peptide bond

(gli-ala)

Di-, tri-, .... polypeptides are called by the name of the amino acids that make up the polypeptide, in which all incoming amino acids as radicals end in - silt, and the last amino acid sounds unchanged in the name.

Resin is obtained by polycondensation of ε - aminocaproic acid or polymerization of caprolactam (lactam ε - caproic acid) capron:

N CH 2 CH 2 [- NH - (CH 2) 5 - CO - NH - (CH 2) 5 - CO -] m

caprolactam polycaprolactam (kapron)

This resin is used in the production of synthetic nylon fiber.

Another example of a synthetic fiber is enant.

Enanth is a polyamide of enanthic acid. The enant is obtained by polycondensation of 7-aminoheptanoic acid, which is in the reaction in the form of an internal salt:

N N + H 3 - (CH 2) 6 - COO - [ - NH - (CH 2) 6 - CO -] n + n H 2 O

Enanth is used for the manufacture of synthetic fiber, in the production of "artificial" fur, leather, plastics, etc. Enanth fibers are characterized by high strength, lightness and elasticity.

Tests for self-control of knowledge on the topic: "Amino acids"

1. Name the compound according to the systematic nomenclature

CH 3 - CH - COOH

A) 2-aminopropanoic acid

B) a-aminopropionic acid

C) a-alanine

D) 2-aminopropionic acid

2. Name the compound according to historical nomenclature

CH 3 - CH - CH - COOH

A) a-amino - b- methylbutyric acid

B) a-methyl - b- aminobutyric acid

C) 2-amino-3-methylbutanoic acid

D) 2-methyl - 3 - aminobutanoic acid

3. Alanine H NH 2 belongs to the series

4. The reaction products are

CH 2 - COOH PCl 5 B

NH2 NH3 C

A) A: CH 2 - COONa; B: CH 2 - COCl; C: CH 2 - CONH 2

B) A: CH 2 - COONa; B: CH 2 - COCl 2; C: CH 2 - CONH 4

C) A: CH 2 - COONa; B: CH 2 - COOH; C:CH-NH2

D) A: CH 2 - COONa; B: CH 2 - COOH; C: CH 2 - CONH 2

NH 2 N + H 3 Cl - NH 2

5. The reaction products are

CH 2 - COOH CH 3 Br B

NH2 CH3COCl C


HNO 2 D

A) A: CH 2 - COOH; B: CH 2 - COOH; C:CH2-COOH; D: CH 2 - COOH

N + H 3 Cl - NHCH 3 NH - COCH 3 OH

B) A: CH 2 - COOCl; B:CH2-COOCH3; C:CH2-COOH; D: CH 2 - COOH

NH 2 NH 2 NH-COCH 3 ; Oh

C) A: CH 2 - COCl 2; B: CH 2 - COOH; C:CH2-COOH; D: CH 2 - COOH

NH 2 NH-CH 3 NH - COCH 3 NH-N \u003d O

D) A: CH 2 - COCl 2; B: CH2—COBr; C:CH2-COOH; D: CH 2 - COOH

NH 2 NH 2 NH - COCH 3 OH

6. a-Amino acids form when heated

A) lactams

B) ketopiperazines

C) lactones

D) lactides

7. b-amino acids form when heated

A) unsaturated acids

B) ketopiperazines

C) lactams

D) lactones

8. g-amino acids form when heated

A) lactams

B) unsaturated acids

C) lactides

D) lactones

9. During the polycondensation of amino acids,

A) peptides

C) piperazines

D) polyenes

10. Peptide bond in protein molecules is

11. Polycondensation differs from polymerization:

A) No formation of by-products of low molecular weight

B) Formation of by-products of low molecular weight

C) Oxidation

D) Decay

12. A qualitative reaction to a-amino acids is reaction c:

A) ninhydrin

B) a-naphthol

13. The reaction products in the Strecker-Zelinsky synthesis are named:

CH 3 HCN NH 3 2 HOH (HCl)

CH = O A B C

A) A-α-oxynitrile butyric acid; B- α-aminonitrile of butyric acid; C-

D, L -alanine;

B) A-α-oxynitrile propionic acid; B-α-aminonitrile of aminopropionic acid; C-D, L-alanine;

C) A-α-hydroxynitrile of valeric acid; B-α-aminonitrile of valeric acid;

C-D, L - threonine;

D) A-α-oxynitrile propionic acid; B-α-aminonitrile of propionic acid; C-

D, L - alanine.

14. Name the substances in the chain of transformations:

COOC 2 H 5 O \u003d N-OH [H] (CH 3 CO) 2 O C 2 H 5 ONa

CH 2 - H2O BUT - H2O AT - CH3COOH FROM - C2H5OH D

malonic ether

Cl-CH 2 -CH (CH 3) 2 H 2 O (HCl) t 0

–NaCl E - CH3COOH, AND - CO2 Z

–2C2H5OH

A) A-nitrosomalon ester; B - oximmalonic ether; C-N-acetyloxymalonic ester; D-Na-N-acetyloxymalonic ester; E-isobutyl-N-acetyloxymalonic ester; G-isobutyloximmalonic ether; 3-isoleucine;

C) A-nitrosomalon ester; B - iminomalonic ether; C-N-acetyliminomalone ester; D-Na-N-acetyliminomalone ester; E-isobutyl-N-acetyliminomalone ester; G-isobutyliminomalonic ether; 3-threonine;

C) A-nitrosomalon ester; B-aminomalonic ether; C-N-acetylaminomalon ester; D-Na-N-acetylaminomalon ester; E-isobutyl-N-acetylaminomalon ester; G- isobutylaminomalone ether; Z-leucine;

D) A-oximmalonic ester; B - nitrosomalon ether; C-N-acetylnitrosomalon ester; D-Na-N-acetylnitrosomalon ester; E-isobutyl-N-acetylnitrosomalon ether; G-isobutylnitrosomalon ether; Z-valine.

CARBOHYDRATES

Carbohydrates are a large group of organic substances widely distributed in nature. These are glucose, sucrose, starch, cellulose and so on.

Every year, plants on our planet create a huge mass of carbohydrates, which is estimated at a carbon content of 4 * 10 10 tons. About 80% of the dry matter of plants is carbohydrates and 20-30% is animal organisms.

The term "carbohydrates" was proposed in 1844 by K. Schmidt, since most of these substances correspond to the formula C n (H 2 O) m. For example, a glucose molecule has the formula C 6 H 12 O 6 and is equal to 6 carbon atoms and 6 water molecules. Later, carbohydrates were found that did not correspond to this composition, for example, deoxyhexose (C 6 H 10 O 5), but the term has survived to this day.

Carbohydrates are divided into two large groups - these are simple carbohydrates or monosaccharides (monoses), substances that do not undergo hydrolysis, for example, glucose, fructose. In nature, pentoses and hexoses are more common. The second group is complex carbohydrates, which, when hydrolyzed, give monosaccharides. Complex carbohydrates, in turn, are divided into oligosaccharides and polysaccharides. Oligosaccharides consist of two to ten monose residues. "Oligos" means "few" in translation. The simplest oligosaccharides are disaccharides (bioses), consisting of two monose residues. For example, sucrose C 6 H 12 O 6 consists of residues of two monoses: glucose and fructose. Oligosaccharides consisting of residues of three monoses are called trioses, those of four are called tetraoses, and so on. Polysaccharides (polyoses) are formed from monoses as a result of their polycondensation. That is, polyoses are heterochain polymers or biopolymers, the monomers of which are monoses. Heterochain polymers contain in their chain not only carbon atoms, but also oxygen atoms, for example:

NC 6 H 12 O 6 (C 6 H 10 O 5) n + (n-1) H 2 O or (-C 6 H 10 O 4 - O -) n

Carbohydrates

Examples of problem solving

There are two main ways to obtain macromolecular compounds: polymerization and polycondensation.

Polymerization- the reaction of the connection of monomer molecules, which proceeds due to the breaking of multiple bonds.

Polymerization can be represented by the general scheme:

where R is a substituent, for example, R \u003d H, - CH 3, Cl, C 6 H 5, etc.

n is the degree of polymerization.

The polymerization of alkadienes with conjugated double bonds (alkadienes-1,3) proceeds by opening double bonds in positions 1,4 or 1,2, for example:

The most valuable polymers (rubbers) are obtained by stereoregular polymerization in the 1,4-position in the presence of Ziegler-Natta catalysts:

To improve the properties of rubbers, the polymerization of 1,3-butadiene and isoprene is carried out together with styrene, acrylonitrile, and isobutylene. Such reactions are called copolymerizations. For example,

where R = - (butadiene - styrene rubber),

R \u003d -C º N (butadiene - nitrile rubber).

Polycondensation is a reaction of the formation of macromolecules from di or polyfunctional compounds, accompanied by the elimination of low molecular weight products (water, ammonia, hydrogen chloride, etc.).

A polycondensation involving only one monomer is called a homopolycondensation. For example,

nHO - (CH 2) 6 - COOH (n-1) H 2 O + H - [-O - (CH 2) 6 -CO -] n - OH

7-hydroxyheptane polymer

acid (monomer)

As a result of homopolycondensation of 6-aminohexanoic acid

(e-aminocaproic acid), a capron polymer is obtained.

A polycondensation involving two monomers containing different functional groups is called a heteropolycondensation. For example, polycondensation between dibasic acids and dihydric alcohols leads to the production of polyesters:

nHOOS - R - COOH + nHO - R¢ - OH [- OC - R - COOR¢ - O -] n + (2n-1) H 2 O

As a result of the heteropolycondensation of adipic acid and hexamethylenediamine, polyamide (nylon) is obtained

Example 1

How many structural units (n) are included in a PVC macromolecule with a molecular weight of 350,000?



M m polymer = 350000

Determine the number of structural links - (n).

1. Reaction scheme:

2. Find the molecular weight of the elementary unit

by adding the atomic masses of the elements that make up its composition - 62.5.

3. Find (n). We divide the molecular weight of the elementary unit: 3500: 62.5 = 5600

Answer: n = 5600

Example 2

Write a scheme for the formation of isobutylene dimer and trimer under the action of sulfuric acid, taking into account the mechanism of this reaction (cationic polymerization).

Such a polymerization process was observed for the first time by A.M. Butlerov under the action of sulfuric acid on isobutylene.

Chain termination in this case occurs as a result of the elimination of a proton (H +).

The reaction takes place in the presence of water, which captures a proton, forming a hydronium cation.

Control tasks

191. What polymers are called thermoplastic, thermoset?

192. Write an equation for the reaction of copolymerization of styrene

C6H5–CH=CH2 and butadiene CH2=CH–CH=CH2. What properties does the copolymerization product have and where is it used?

193. Write the reaction equations for the polymerization of propylene

CH2=CH–CH3 and isobutylene H2C=C–CH3.

194. Write the equation for the polycondensation reaction of adipic acid HOOC(СH2)4COOH and hexamethylenediamine NH2(СH2)6NH2. What product is formed, what properties does it have and where is it used?

195. What hydrocarbons are called dienes? Give examples. What is the general formula for the composition of diene hydrocarbons? Draw a polymerization scheme for one of the diene hydrocarbons.

196. What compounds are called amines? Draw a scheme for the polycondensation of adipic acid and hexamethylenediamine. What is the name of the polymer formed as a result of this reaction?

197. Calculate the molecular weight of PVC if the degree of polymerization is 200. Write the reaction equation for the polymerization of vinyl chloride.

198. What compounds are called amino acids? Write the formula for the simplest amino acid. Draw a scheme for the polycondensation of aminocaproic acid. What is the name of the polymer formed as a result of this reaction?

199. Write the reaction equations for the production of capron from aminocaproic acid NH2(CH2)5COOH and nylon from adipic acid COOH(CH2)4COOH and hexamethylenediamine NH2(CH2)6NH2.

200. What is the name of the hydrocarbons represented by isoprene? Draw a scheme for the copolymerization of isoprene and isobutylene.