Век химии (Английский язык для студентов химического профиля). Учебное пособие

7. Возможно, что нам удастся открыть секреты фотосинтеза, для того чтобы солнечный свет превращал двуокись углерода в сахар.

Text C

1. Pay attention to the following words and word combinations:

marketability – товарность, пригодность для продажи; «brushability» – пригодность для работы кистью: brush marks – мазки, следы кисти;

adequately – соответствующим образом, равномерно; similarly – аналогично;

rheology – реология; conventional – обычный;

shear – отслаивать, лишать чего-либо; «drilling muds» – бурильная смазка (шлам); to lubricate – смазывать;

drill bit – бурильное сверло: rock chips – осколки породы; oil well – нефтяная скважина; at rest – в состоянии покоя; foodstuffs – пищевые продукты; in respect to – относительно.

2. Read the text and be ready to say if the following statements are true or false. Use the following phrases:

I think it’s right.

It seems to be wrong.

I can’t agree with it.

As far as I know …

To my mind

On the contrary

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1.If the paint is too thin it will adequately cover a surface.

2.The art of paper coating is dependent on the rheology of the coating material.

3.The petroleum industry uses small quantities of “drilling muds”.

4.Muds should exhibit viscosity under shearing.

5.Most foodstuffs are non-newtonian in behaviour.

SOME APPLICATIONS OF A POLYMER

In many cases the marketability of a polymer is due to the rheologically complex behaviour of the material. An example can be found in the compounding of materials for coating of surfaces. The non-newtonian behaviour of paints is an important factor in determining the «brushability» of a paint. Interesting tests have been devised to measure this quality in the laboratory. One wishes to have a paint that will not show brush marks after drying; on the other hand, if the paint is too thin it will not adequately cover a surface. Similarly, the art of paper coating is highly dependent on the rheology of the coating material. In conventional coating applications the coating “colour”, as it is called, is subjected to extreme variations of high and low shearing.

The petroleum industry uses large quantities of “drilling muds” to lubricate the drill bit and to carry rock chips out of the hole during of oil wells. It is important to have muds which exhibit low viscosity under sharing but which are very thick at rest, thus preventing rapid settling of chips when the drilling unit is not in operation.

Further examples can be given almost without limit. We note that most foodstuffs are non-newtonian. This is important in respect both to food processing and to the preparation of acceptable natural food substitutes.

3.Make up the plan of the text.

4.Give a brief summary of the text.

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Text D

1. Read the text and choose the most suitable title out of the given once.

a)The “Big Six”.

b)Six Polymers.

c)Plastics.

In spite of polyethylene’s range of properties and many uses, it cannot fill all the roles we assign to plastics. It melts at a low temperature, it is permeable to gases, it swells in the presence of oil or organic solvents, it is very transparent, and it is very expensive to make polyethylene crystalline enough to be exceptionally rigid and strong.

Today, more than 60,000 plastics are known. Most have been developed for special purposes ranging from fry pan coatings to resins for restoring antiques. Yet, the two types of polyethylene (LDPE and HOPE) and four other polymers make up the bulk of the plastics you regular encounter. Approximately 20 million tons of these six polymers are made annually in the United States, and they account for about 63 % of all plastics used in this country. In addition to polyethylene, the other four plastics are polypropylene, polystyrene, polyvinyl chloride (PVC), and polyethylene terephthalate (PET). All are ultimately based on petroleum.

No discussion of polymers can be complete without including one of the most important classes of natural polymers and the synthetic substitute that brilliantly duplicates some of the properties of the natural material. The naturally occurring polymer is protein. Actually there is a wide variety of these biological macromolecules that make up our skin, hair, muscle and enzymes. All proteins are polyamides, which are polymers of amino acids. As the name suggests, molecules of amino acids contain both amine groups (-NH2) and acidic groups (-COOH). A general formula for an amino acid is given below. The amine and acid groups are both attached to the same carbon atom. In addition, a hydrogen atom and another group (represented by an R) are bonded to the same carbon.

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The 20 amino acids found in most proteins differ in the identity of the R group. In some amino acids, R consists of carbon and hydrogen atoms, as in alanine, where R is a methyl group. In others, R also includes oxygen, nitrogen, or sulfur atoms. Some R groups are acidic and some are basic.

2. Write out.

a)key worlds and terms;

b)the sentences expressing the main idea of each paragraph.

Unit 9

GRAMMAR: Participles.

1. a) Using a dictionary translate the following words, word combinations and chemical terms into Russian:

substance, milky dispersion, terpenes, steroids, chemical compounds, reversible, isoprenoid, acetic acid, latex vessels, fine structure, basic building block, gross molecules, coagulate, bulk.

b) Determine the forms of participles and their synthetic function, translate into Russian:

1.Having established the reasons we can proceed with our regular work in this matter.

2.The professor told the students about the experiments being carried out in the laboratory.

3.The figures mentioned in the report were published in the latest scientific journal.

4.When studying elements Mendeleyev found that they could be divided into nine groups.

5.It is a common observation that bodies expand when heated.

6.I haven’t heard any of those factors mentioned.

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7.As pointed out previously, the explanation given is by no means complete.

8.In general the compounding and processing methods used for all the SBR types are similar to those of natural rubber.

9.Solid bodies offering resistance to a change in form or size exhibit the property of recovery.

10.While rubbing two pieces of metal we may produce heat.

2. Put the words in the correct order to form sentences.

1.found, elastic, is, natural, substance, rubber, an, as, species, many, dispersion, in, of, plants, milky.

2.synthetic, chemical, rubbers, range, are, high, manufactured, compounds, from, polymeric, elastic, substances, a, of, wide.

3.terpenes, occurring, natural, related, naturally, many, rubber, chemically, is, closely, including, to, steroids, other, compounds, and.

4.coagulated, latex, collected, bulked, is, and.

5.first, wild, Brazil, obtained, rubber, trees, was, from, in.

Text A

3. Read the text and translate it using a dictionary.

RUBBER

Natural rubber is an elastic substance found as milky dispersion in many species of plants. Synthetic rubbers are high polymeric elastic substances manufactured from a wide range of chemical compounds. Both synthetic and natural rubbers have in common the ability to undergo nearly reversible, highly elastic deformations.

Natural rubber is closely related chemically to many other naturally occurring compounds, from animals as well as plants, including terpenes and steroids. These are known collectively as isoprenoids. The basic building block for natural rubber as well as other polyisoprenoids is acetic acid. Natural rubber occurs in a separate system of latex vessels just under the outer bark. Latex is

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collected, bulked and coagulated. Rubber was first obtained from wild trees in Brazil.

The physical and chemical properties of natural rubber are fixed by biological factors. In synthetic rubber a much greater variation of properties can be realized. However, in both natural and synthetic rubber the properties are resultant contributions of the fine structures and of the gross molecules of the polymer. The chemical properties of rubber are of paramount importance.

4. Answer the questions.

1.What is natural rubber?

2.What are synthetic rubbers manufactured from?

3.What is the main property of both natural and synthetic rubber?

4.Where does natural rubber occur?

5.In what country was natural rubber first obtained?

6.What are the physical and chemical properties of natural rubber fixed by?

5. Complete the following sentences using some active words and word combinations (see below).

1.The basic building block for natural rubber is …

2.Rubber … from wild trees in Brazil.

3.… is closely related to many compounds, including terpenes and steroids.

4.The physical and chemical … of natural rubber are fixed by biological factors.

5.Natural rubber occurs in a separate system of ….

6.Latex is collected, bulked and ….

7.Synthetic rubbers are high polymeric elastic substances manufactured from a wide range of …

8.Both synthetic and natural rubbers have in common … to undergo highly elastic deformations.

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Chemical compounds, natural rubber, was first obtained, the ability, coagulated, acetic acid, latex vessels, properties.

6. Retell the text using the scheme (see Un.1).

Text B

1. Match the English words and word combinations in A with their Russian equivalents in B.

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2. Read the text trying to understand its main idea.

SYNTHETIC RUBBER

There is only one rubber obtained from natural sources in commercial quantities. There are several synthetically produced compounds that are classed as rubbers.

The butadiene-styrene rubber, now called SBR, constitutes the bulk of the synthetic rubber production. All the SBR-type rubbers are obtained by the emulsion polymerization of butadiene and styrene in various ratios. However, in the most commonly used type the ratio of butadiene and styrene is approximately 78: 22.

The original or hot SBR is polymerized at a temperature of 122 ºF or higher and is used primarily for mechanical, goods.

The cold type, polymerized at 41 ºF, exhibits an improvement over the hot type in most physical properties. When used in light-duty tyres such as passenger car tyres, the cold-rubber compounds have proved equal or superior to natural rubber treads. However, they are inferior to natural rubber for truck tyres because of the greater heat build-up during flexion.

In general the compounding and processing methods used for all the SBR types are similar to those of natural rubber. Although natural rubber is superior with respect to lower heat build-up, resilience, and hot strength, the SBR types are more resistant to abrasion and weathering. However, carbon black or some other reinforcing fillers must be added to the butadiene-styrene rubber to develop the best physical qualities.

3.Divide the text into some logical parts and entitle them.

4.Translate the following sentences into English using lexical material of the text.

1.Существует всего лишь один вид каучука, получаемый в промышленных масштабах из природных источников.

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2.Низкотемпературный каучук превосходит высокотемпературный по многим физическим свойствам.

3.Каучуки типа СКБ – более стойкие к стиранию и воздействию погодных условий по сравнению с натуральными каучуками.

4.Высокотемпературный каучук используется, главным образом, для производства механических изделий.

6.Полимеризация исходного или высокотемпературного каучука происходит при t 122 ºF (по Фаренгейту).

7.Низкотемпературный каучук уступает по качеству натуральному каучуку.

8.Все типы СКБ каучуков получают при эмульсионной полимеризации бутадиена и стирола в различной пропорции.

Text C

1.Pay attention to the following words and word combinations.

contributing factors – основополагающие факторы;

mixing process – процесс приготовления резиновой смеси; mixed compound – смешанное соединение;

quality of raw materials – качество сырья;

consistency of products – консистенция (состав) продуктов; carbon black – сажа;

end-user – конечный пользователь; fillers – наполнители;

elimination – исчезновение;

feasible for smb. – возможный для кого-либо.

2.Read the text and be ready to say if the following sentences are true or false. Use the following phrases.

As far as I know …

It seems to be wrong (right) …

I cant’t agree with you …

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I’m afraid you are mistaken …

On the contrary …

That’s right …

1.The major raw materials of the rubber industry are rubber, carbon black, different fillers, oils and various chemicals.

2.There hasn’t been a great change concerning high quality and consistency of products in the rubber industry during last decades.

3.The quality of raw materials doesn’t influence on the efficiency of the mixing process.

4.The degree of control of the mixing process is very important for the quality of the mixing compound.

5.Many rubber processors today have in place a supplier accreditation system, or audit.

6.The service of audit doesn’t lead to reduction of incoming raw material testing.

7.The automotive industry is one of the end-users of product made by rubber industry.

8.The processors of rubber industry have to establish the minimum requirements for supplier.

MIXING EFFICIENCY AND QUALITY:

A VIEW FROM A SYNTHETIC RUBBER PRODUCER

There are three contributing factors which, between them, determine both the efficiency of the mixing process and the quality of the mixed compound. These are:

•The quality of the raw materials used;

•The degree of control of the mixing process: and

•The test methods used to assess both raw material quality and the degree of mixing of the compound.

This article will deal with one of these factors. Quality of raw materials

There has been a significant change in emphasis towards high quality and consistency of products in the rubber industry during the 1980s. This change was instigated by the end-user, especially the

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