Polystyrene.

Polystyrene [poli'stairbn] 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 ['poliGfcn] (polyethene, polyethylene) is a

plastic made from ethane [e'Gem]. 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.

Part II

adhesion [эсГЫ: зэп] — прилипание

adhesive [ad'hiiziv] — клей

bond [bond] — связи, узы

insulation [msju'leijan] — изоляция

casting [ka: stin] — литье

void [void] — пустота

solid [solid] — твердое тело, твердый

acid ['aesid] — кислота

alkali [aslkslai] — щелочь

to obtain [ab'tem] — доставать, получать

granule ['graenjud] — гранула

solution [ss'lutjbn] — раствор

lattices ['lsetisiz] — латексы

paste [peist] — паста

yield [ji: ld] — выход

durable ['djuarabi] — прочный

rubber ['глЬэ'] — резина, каучук

garment ['gaimsnt] — предметы одежды

lens ['lenz] — линза

capacitor — эл. конденсатор

syringe [si'rmdj] — шприц

light-duty — неответственный

envelope — зд. обрамление

impact ['impaekt] — удар

improved —* улучшенный

modifiers ['modi'faiaz] — модификаторы

addition [s'dijbn] —добавление

readily f'redili] — легко, с готовностью

foam [faum] — пена

catalyst ['kaetalist] — катализатор

wax [waeks] — воск

reasonable ['riiznsbl] — приемлемый, неплохой

coating ['kautin] — слой, покрытие

UnitS

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 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.