to synthesize -- синтезировать

chemicals -- химические вещества

to soften -- смягчать

cellulose -- клетчатка, целлюлоза

wax -- воск

thermosetting plastics -- термореактивные пластмассы

to harden -- делать твердым

coil -- спираль

stretched -- растянутый

transparent -- прозрачный

rubber -- резина, каучук

to decompose -- разлагаться

soft-drink -- безалкогольный напиток

to subject -- подвергать

polyurethane -- полиуретан

resin -- смола

similar -- сходный, подобный

sufficient -- достаточный

to prevent -- предотвращать

General understanding

1. What is the definition of plastics?

2. What is the basic chemical element in plastics formula?

3. What do polymers consist of?

4. What are long-chain molecules made of?

5. What are the main types of polymers?

6. Give examples of plastics belonging to these types.

7. What plastics are the best electrical insulators?

8. Describe the difference between thermoplastics and thermosets.

9. What are the main types of structures of polymers?

10. What are the most important properties of plastics?

11. Give the examples of various uses of plastics because of their characteristic properties.

Exercise 5.1. Find English equivalents in the text:

1. синтетические полимеры

2. молекулы с длинными цепями

3. характерные свойства полимера

4. синтезируются из органических химических веществ

5. хороший электрический изолятор

6. размягчаться при нагревании

7. затвердевать при охлаждении

8. гибкий и легко растяжимый

9. течь под нагрузкой

10. более высокая плотность

11. менее подвержены ползучести

12. достаточная взаимосвязь между молекулами

Exercise 5.2. Translate into English:

1. Длинные цепи молекул полимеров состоят из одинаковых небольших молекул мономеров.

2. Сополимеры состоят из двух и более мономеров.

3. Пластмассы можно получать в виде листов, тонких пленок, волокон или гранул.

4. Молекулы полимеров могут быть линейными, ветвящимися или с поперечными связями.

5. Малый вес пластмасс и хорошие электроизоляционные свойства позволяют использовать их в радиоэлектронике и электроприборах, а также вместо металлов.

6. Молекулы термопластов имеют извитую форму и, поэтому, они гибкие и легко растяжимы.

7. Эластомеры имеют большое число поперечных связей между молекулами.

Text В: «TYPES OF PLASTICS»

1. Epoxy resin.

Epoxy resin is a thermoset plastic containing epoxy groups. Epoxy resin hardens when it is mixed with solidifier and plasticizer. Plasticizers make a polymer more flexible.

Epoxy resins have outstanding adhesion, toughness, and resistance to attack from chemicals. They form strong bonds and have excellent electrical insulation properties. Large, complex, void-free castings can be made from them. They are also used as adhesives, and in composites for boat building and sports equipment.

2. PVC (polyvinyl chloride)

PVC (polyvinyl chloride) is a thermoplastic polymer made from vinyl chloride is a colourless solid with outstanding resistance to water, alcohols, and concentrated acids and alkalis. It is obtainable as granules, solutions, lattices, and pastes. When compounded with plasticizers, it yields a flexible material more durable than rubber. It is widely used for cable and wire insulation, in chemical plants, and in the manufacture of protective garments. Blow moulding of unplasticized PVC produces clear, tough bottles which do not affect the flavour of their contents. PVC is also used for production of tubes or pipes.

3. Polystyrene.

Polystyrene is a thermoplastic produced by the polymerization of styrene. The electrical insulating properties of polystyrene are outstandingly good and it is relatively unaffected by water. Typical applications include light fixtures, toys, bottles, lenses, capacitor dielectrics, medical syringes, and light-duty industrial components. Extruded sheets of polystyrene are widely used for packaging, envelope windows, and photographic film. Its resistance to impact can be improved by the addition of rubber modifiers. Polystyrene can be readily foamed; the resulting foamed polystyrene is used extensively for packaging.

4. Polythene (polyethene, polyethylene)

Polythene (polyethene, polyethylene) is a plastic made from ethane. It is one of the most widely used important thermoplastic polymers. It was first developed by the polymerization of ethane at a pressure of 2,000 bar at 200°C. This produced low-density polythene (LDPE). A relatively high-density form (HDPE) was synthesized in the 1950s using a complex catalyst. Polythene is a white waxy solid with very low density, reasonable strength and toughness, but low stiffness. It is easily moulded and has a wide range of uses in containers, packaging, pipes, coatings, and insulation.

Vocabulary:

adhesion -- прилипание

adhesive -- клей

bond -- связи, узы

insulation -- изоляция

casting -- литье

void -- пустота

solid -- твердое тело, твердый

acid -- кислота

alkali -- щелочь

to obtain -- доставать, получать

granule -- гранула

solution -- раствор

lattices -- латексы

paste -- паста

yield -- выход

durable -- прочный

rubber -- резина, каучук

garment -- предметы одежды

lens --линза

capacitor -- эл. конденсатор

syringe -- шприц

light-duty -- неответственный

envelope -- зд. обрамление

impact -- удар

improved -- улучшенный

modifiers -- модификаторы

addition -- добавление

readily -- легко, с готовностью

foam -- пена

catalyst -- катализатор

wax -- воск

reasonable -- приемлемый, неплохой

coating -- слой, покрытие

General understanding:

1. What are the types of plastics?

2. What are the features of the epoxy resin?

3. What is epoxy resin used for?

4. What is PVC usually used for?

5. What are the typical applications of polystyrene?

6. When was polyethylen synthesized?

7. Under what conditions is polyethylen synthesized?

8. What sorts of polyethylen can be synthesized?

Exercise 5.3. Translate into Russian:

1. Polythene is a plastic made from ethane.

2. Epoxy resins have outstanding adhesion, toughness and resistance to attack from chemicals.

3. PVC is a colourless solid with outstanding resistance to water, alcohols, and concentrated acids and alkalis.

4. Polystyrene is a thermoplastic produced by the polymerization of styrene.

5. Polythene is a white waxy solid with very low density, reasonable strength and toughness but low stiffness.

Exercise 5.4. Translate into English:

1. Эпоксидная смола затвердевает когда смешивается с отвердителем и пластификатором.

2. Эпоксидные смолы используются в качестве клея, а с добавками -- в строительстве лодок и спортивного снаряжения.

3. ПВХ -- бесцветное твердое вещество с выдающейся устойчивостью к воздействию воды, спиртов, концентрированных кислот и щелочей.

4. ПВХ широко используется при производстве изоляции для проводов.

5. Выдувка непластифицированного ПВХ используется при производстве прозрачных бутылок для напитков.

6. Полистирол легко вспенивается и используется для упаковки.

7. Полиэтилен -- воскообразное вещество белого цвета с очень низкой плотностью и малой жесткостью.

Text С: «COMPOSITE MATERIALS»

The combinations of two or more different materials are called composite materials. They usually have unique mechanical and physical properties because they combine the best properties of different materials. For example, a fibre-glass reinforced plastic combines the high strength of thin glass fibres with the ductility and chemical resistance of plastic. Nowadays composites are being used for structures such as bridges, boat-building etc.

Composite materials usually consist of synthetic fibres within a matrix, a material that surrounds and is tightly bound to the fibres. The most widely used type of composite material is polymer matrix composites (PMCs). PMCs consist of fibres made of a ceramic material such as carbon or glass embedded in a plastic matrix. Usually the fibres make up about 60 per cent by volume. Composites with metal matrices or ceramic matrices are called metal matrix composites (MMCs) and ceramic matrix composites (CMCs), respectively.

Continuous-fibre composites are generally required for structural applications. The specific strength (strength-to-density ratio) and specific stiffness (elastic modulus-to-density ratio) of continuous carbon fibre PMCs, for example, can be better than metal alloys have. Composites can also have other attractive properties, such as high thermal or electrical conductivity and a low coefficient of thermal expansion.

Although composite materials have certain advantages over conventional materials, composites also have some disadvantages. For example, PMCs and other composite materials tend to be highly anisotropic -- that is, their strength, stiffness, and other engineering properties are different depending on the orientation of the composite material. For example, if a PMC is fabricated so that all the fibres are lined up parallel to one another, then the PMC will be very stiff in the direction parallel to the fibres, but not stiff in the perpendicular direction. The designer who uses composite materials in structures subjected to multidirectional forces, must take these anisotropic properties into account. Also, forming strong connections between separate composite material components is difficult.

The advanced composites have high manufacturing costs. Fabricating composite materials is a complex process. However, new manufacturing techniques are developed. It will become possible to produce composite materials at higher volumes and at a lower cost than is now possible, accelerating the wider exploitation of these materials.

Vocabulary:

fibreglass -- стекловолокно

fibre -- волокно, нить

reinforced -- упрочненный

expansion -- расширение

matrix -- матрица

ceramic -- керамический

specific strength -- удельная прочность

specific stiffness -- удельная жесткость

anisotropic -- анизотропный

General understanding:

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