Synthetic rubber

RUBBER

THE WORLD OF RUBBER

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.

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

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.

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.

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.

5. Для улучшения физических качеств бутадиен-стирольного каучука в него добавляют (газовую) сажу и некоторые другие наполнители усиливающего действия.

6. Полимеризация исходного или высокотемпературного каучука происходит при t 122º 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 …

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 suppliers.

MIXING EFFICIENCY AND QUALITY:

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