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 PVC protective 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 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 200C. 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 – 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 under striding:

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 polyethylene synthesized?

7. Under what conditions is polyethylene synthesized?

8. What sorts of polyethylene ca be synthesized?

Translate into native language.

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.

Translate into English

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

2. Эпоксидные смолы используется 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 – воскообразные вещество белого цвета с очень низкой плотностью и малой жесткостью.

Lesson 15