Век химии (Английский язык для студентов химического профиля). Учебное пособие

peroxide – перекись;

modified phenols – модифицированные фенолы; high energy radiation – радиация с высокой энергией.

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 can’t agree with you …

I’m afraid you are mistaken …

On the contrary …

That’s right …

1.Charles Goodyear tried to improve the properties of rubber.

2.Vulcanization is a process of making raw rubber useful.

3.Vulcanization makes weak bonds between the long linear molecules of the rubber polymer.

4.Selenium is the most used vulcanizing agent.

5.Antioxidants are used for final product protection against the effects of light, heat and oxygen.

VULCANIZATION

Starting in 1831, an American Charles Goodyear carried out a great many experiments in attempts to improve the properties of rubber. He tried to discover a ‘drier’, which would prevent manufactured goods from becoming sticky. In 1839 he made an observation, which was to revolutionize the industry he found that if crude rubber is treated with sulphur above the melting point of the latter, it undergoes a change, which produces a marked improvement in its mechanical properties and also in its ability to withstand changes in temperature.

Vulcanization is a process used to make raw rubber useful; it decreases sensitivity to extremes of temperature, confers resistance to flow under stress, and stabilizes rubber’s valuable properties; e. g. abrasion resistance, resilience, and impermeability to fluids.

91

Chemically, vulcanization creates strong bonds between the long linear molecules of the rubbery polymer, efficiently fixing the molecules’ position with respect to one another, and preventing their slippage under stress. Solid rubber is prepared for vulcanization by a process known as compounding, i. e. mixing with other ingredients in internal mixers which uniformly blend the rubber and the added ingredients. Sulphur is the most used vulcanizing agent. Other rnaterials commonly added before vulcanization include: accelerators to speed vulcanization, zinc oxide and fatty acid to improve properties, carbon black or other fillers to strengthen the final product, and antioxidants to protect against effects of light, heat, and oxygen.

The fully compounded rubber is extruded or calendered (depending on the properties wanted) to the final form, and then vulcanized. This usually is done in a mould with the aid of heat, although some mixtures permit cure at room temperature.

Vulcanizing agents besides sulphur are often used, particularly for some heat and solvent resistant rubbers, including peroxides, modified phenols and metallic oxides. Some types of rubber have been vulcanized experimentally by high energy radiation.

3.Make up the plan to the text.

4.Give a brief summery of the text.

Text D

1. Read the text and choose the most suitable title out of the given ones:

a)Storage Hardening.

b)Hardening.

c)Rubber hardness.

The presence of microgel particles in natural rubber latex has a directly practical consequence in the phenomenon of storage hardening. Rubber, either in the form of latex or solid sheet, when stored for considerable periods develops an increased hardness (as

92

measured by Mooney viscosity or Williams plasticity), the change in solid sheet being generally greater the lower the initial hardness.

The changes are greatly influenced by the relative humidity of storage. In dry air the rate at which hardening occurs increases with decreasing sample thickness or with increasing temperature. The removal of acetone-soluble and nitrogenous components does not prevent the hardness increase.

One might expect that the increase in hardness which occurs when ammoniated latex is stored is a result of intra-particle crosslinking and microgel formation. With solid rubber the crosslinking process is no longer confined to within the original latex particles, but there is no reason to suppose that the mechanism of the crosslinking reaction differs in the two cases.

Although the nature of the spontaneous hardening reaction remains obscure considerable information about the functional groups involved and on methods of control have recently been forthcoming. Rubber hydrocarbon interacts with oxygen to form hydroperoxidic compounds and the decomposition of such compounds could result either in degradation or crosslinking of the rubber molecules, according to conditions. However, crosslinking via hydroperoxide decomposition does not appear to be a major cause of storage hardening. Since hardening can be almost completely suppressed by the addition to latex of monofunctional carbonyl reagents (especially dimedone which is a specific reagent for aldehyde groups) it has been inferred that the crosslinking reaction involves carbonyl groups in the rubber. The number of such carbonyl groups per rubber molecule can be estimated by measuring the concentration of hydroxylamine required to inhibit completely storage hardening; values of 9-29 were found for a number of clonal rubbers. Difunctional amines, such as benzidine, in contrast to their monofunctional analogues, promote crosslinking by coupling reactions.

If it is accepted that storage hardening results from the presence of carbonyl groups in very small proportions, it is then desirable to determine how these groups originate. It has been suggested that they are incorporated at intervals along the “hydrocarbon chain”, but it has still to be shown that they are an integral feature of natural rubber molecules. Biologically induced oxidation could proceed in the

93

vicinity of the tapping cut or in the latex vessels. The generation of oxygenated groups in secondary reactions is consistent with our present knowledge of polyisoprene biosynthesis.

2. Write out:

a)the key word and terms;

b)the sentences expressing the main idea of each paragraph.

Unit 11

GRAMMAR: Absolute Participial Construction.

1. Translate the following sentences into Russian, paying

Вода представляет собой химическое соединение кислорода и водорода, причем водород образует две трети ее объема.

Rain falling on the ground, the soil absorbs the water.

Когда дождь падает на землю, почва поглощает воду.

1. The salt separates from freezing water, the ice being quite

pure.

2.Water is never absolutely pure in nature, the amount of impurities depending on the locality.

3.The experiments with water containing substances being very interesting, we worked readily.

4.The range of water application being very wide, the scientists are interested in them.

5.The experiment being very difficult, he has to spend much time in the laboratory.

6.Rain water being examined with a magnifying glass, they saw many impurities.

94

7.A gas can be dissolved in liquid, the latter changing its boiling point.

8.All the properties of the element having been described, it was easier to use it.

9.A gas can be dissolved in a liquid, the liquid changing its boiling point.

10. Simple substances consist of atoms, each substance having its own special atom.

2. Put the words in the correct order to form sentences with Absolute Participial Construction.

1.Having, a, long, carried, experiments, of, been, series, out, they, what, determined, would, modifications, be, necessary, equipment.

2.Combines, oxygen, most, with, elements, being, the, product, an, oxide, formed, called.

3.Gas, the, colourless, being, did, we, formation, not, its,

notice.

TEXT A

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

ENVIRONMENTAL ENGINEERING

Environmental engineering is the application of science and engineering principles to improve the environment (air, water, and/or land resources), to provide healthy water, air, and land for human habitation and for other organisms, and to remediate polluted sites.

Environmental engineering involves water and air pollution control, recycling, waste disposal, and public health issues as well as a knowledge of environmental engineering law. It also includes studies on the environmental impact of proposed construction projects.

Environmental engineers conduct hazardous-waste management studies to evaluate the significance of such hazards, advise on treatment and containment, and develop regulations to prevent

95

mishaps. Environmental engineers also design municipal water supply and industrial wastewater treatment systems as well as being concerned with local and worldwide environmental issues such as the effects of acid rain, ozone depletion, water pollution and air pollution from automobile exhausts and industrial sources.

At many universities, Environmental Engineering programs follow either the Department of Civil Engineering or The Department of Chemical Engineering at Engineering faculties. Environmental "civil" engineers focus on hydrology, water resources management and water treatment plant design. Environmental "chemical" engineers, on the other hand, focus on environmental chemistry, advanced air and water treatment technologies and separation processes.

Ever since people first recognized that their health and wellbeing were related to the quality of their environment, they have applied thoughtful principles to attempt to improve the quality of their environment. The ancient civilization utilized early sewers in some cities. The Romans constructed aqueducts to prevent drought and to create a clean, healthful water supply for the metropolis of Rome. In the 15th century, Bavaria created laws restricting the development and degradation of alpine country that constituted the region's water supply.

Modern environmental engineering began in London in the mid19th century when Joseph Bazalgette designed the first major sewerage system that reduced the incidence of waterborne diseases such as cholera. The introduction of drinking water treatment and sewage treatment in industrialized countries reduced waterborne diseases from leading causes of death to rarities.

Briefly speaking, the main task of environmental engineering is to protect public health by protecting (from further degradation), preserving (the present condition of), and enhancing the environment.

4. Answer the questions.

1.What kind of science is environmental engineering?

2.What do environmental engineers conduct hazardous-waste management studies for?

96

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

CHEMICAL ENGINEERING

Chemical engineering is the branch of engineering that deals with the application of physical science (e.g. chemistry and physics), with mathematics, to the process of or chemicals into more useful or valuable forms. In addition to producing useful materials, chemical engineering is also concerned with pioneering valuable new materials and techniques, an important form of research and development. A person employed in this field is called a chemical engineer.

Chemical engineering largely involves the design and maintenance of chemical processes for large-scale manufacture. Chemical engineers in this branch are usually employed under the title of process engineer. A related term with a wider definition is chemical technology. Chemical engineers design processes to ensure the most economical operation. This means that the entire production chain must be planned and controlled for costs. A chemical engineer can both simplify and complicate "showcase" reactions for an economic advantage.

Chemical engineering is applied in the manufacture of a wide variety of products. The chemical industry proper manufactures inorganic and organic industrial chemicals, ceramics, fuels and petrochemicals, agrochemicals (fertilizers, insecticides, herbicides), plastics and elastomers, oleochemicals, explosives, detergents and detergent products (soap, shampoo, cleaning fluids), fragrances and flavors, additives, dietary supplements and pharmaceuticals. Closely allied or overlapping disciplines include wood processing, food processing, environmental technology, and the engineering of petroleum, glass, paints and other coatings, inks, sealants and adhesives.

The individual processes used by chemical engineers (eg. distillation or filtration) are called unit operations and consist of chemical reactions, mass-, heatand momentumtransfer operations. Unit operations are grouped together in various configurations for the purpose of chemical synthesis and/or chemical separation. Some

98

processes are a combination of intertwined transport and separation unit operations, (e.g. reactive distillation).

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. Химическое машиностроение является важной отраслью инженерного искусства.

2. Инженеры-химики разрабатывают экономически выгодные процессы и аппараты.

3.Химическая промышленность производит органические

инеорганические химические продукты.

4.Химическая индустрия тесно связана с деревообрабатывающей, пищевой, фармацевтической и другими видами промышленности.

5.Тепло- и массоперенос являются одними из основных процессов в химической технологии.

TEXT C

1.Pay attention to the following words and word combinations: a vessel – сосуд

multiple aspects – многочисленные вопросы yield of product – выпуск продукции

continuous reactors – реактор непрерывного действия batch reactors – реактор периодического действия transient state – переходный режим

process variables – технологические параметры

2.Read the text and be ready to say if the following statements are true or false. Use the following phrases:

It seems to be wrong (right) …

As far as I know …

Far from it. …

99

If I am not mistaken…

To my mind…

It’s not true to the fact.

1. Сhemical reactors are pipes for chemical reactions maintenance.

2.There are two main basic vessel types: a tank and a pipe.

3.Both types of reactors are run only at a transient state.

4.Batch reactor model, CSTR and PFR are main basic models used to estimate the most important process variables of different chemical reactors.

5.Catalytic reactors don´t require separate treatment.

CHEMICAL REACTORS

In chemical engineering, chemical reactors are vessels designed to contain chemical reactions. The design of a chemical reactor deals with multiple aspects of chemical engineering. Chemical engineers design reactors to maximize net present value for the given reaction. Designers ensure that the reaction proceeds with the highest efficiency towards the desired output product, producing the highest yield of product while requiring the least amount of money to purchase and operate. Normal operating expenses include energy input, energy removal, raw material costs, labor, etc. Energy changes can come in the form of heating or cooling, pumping to increase pressure, frictional pressure loss (such as pressure drop across a 90o elbow or an orifice plate), agitation, etc.

There are two main basic vessel types: a tank and a pipe.

Both types can be used as continuous reactors or batch reactors. Most commonly, reactors are run at steady-state, but can also be operated in a transient state. When a reactor is first brought back into operation (after or in operation) it would be considered to be in a transient state, where key process variables change with time. Both types of reactors may also accommodate one or more solids (reagents, catalyst, or inert materials), but the reagents and products are typically liquids and gases.

100