Unit 9 the world of rubber

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.

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.

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

Text A

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 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.

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.

A B

natural source	низкотемпературный (каучук)
hot type	покрышки для грузовиков
reinforcing filler	природный источник
light-duty tyres	воздействие внешних условий
cold-rubber compounds	сгибание
emulsion polymerization	теплообразование
natural rubber treads	прочность при нагреве
truck tyres	эластичность
cold type	высокотемпературный каучук
heat build-up	стирание
flexion	эмульсионная полимеризация
compounding and processing methods	протекторы из натурального каучука
resilience	покрышки для небольших нагрузок
hot strength	наполнитель усиливающего действия
weathering	методы приготовления смеси и производственный процесс
abrasion	смеси низкотемпературного каучука

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