The nature of polymeric materials

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organic polymers, man-made polymers, natural organic products, complexity of molecules, structural materials, resistant to corrosion, satisfactory resistance, ancient times, an electron microscope, principal products.

Life depends fundamentally on organic polymers. These polymers provide not only food but also clothing, shelter, packaging and transportation.

Indeed nearly all the material needs of man could be supplied by natural organic products. The list of these materials and things made of them might be very long: wood, fur, leather, wool, cotton, silk, rubber, oils, paper, paints and so on. The organic polymers from which such things could be made include proteins, cellulose, starch, resins, and a few other classes of compounds.

Because of the complexity and fragility of their molecules, the natural organic polymers, although known and used for ages, defied attempts to analyse their molecular structure until very recently.

Modern methods of physical and chemical analyses have uncovered the principles that govern the properties of the natural polymers.

On the basis of the discovery involved a new industry of man-made organic polymers has appeared. One could list the principal products: such as fibres, synthetic rubbers, coatings, adhesives and a lot of materials called "plastics". Plastics and synthetic coating are already in common use. It is desirable that they should be used on a large scale, and get further development.

Synthetic polymers now available already possess several of the properties required in a structural material. They are light in weight, easily transported, easily repaired, highly resistant to corrosion and solvents, and satisfactorily resistant to moisture. It would be necessary to add that they have long-lived durability and resistance to high temperatu­res. A very important question could arise whether synthetic polymers could be made inexpensive enough to compete with the structural materials such as metals and ceramics. The answer could be – "yes".

It might seem odd that man came rather late to the investigation of organic polymers as the principal means of supporting life. The natural polymers such as proteins, cellulose and other dominated his existence and even in ancient times people used these materials.

Yet as late as the end of the 19th century polymer chemistry got little attention. Chemists attacked sugar, glycerol, fatty acids, alcohol and other ordinary organic compounds – dissolving, precipitating, crystallizing and distilling them to learn what these substances were composed of. But only feeble efforts were made to investigate such common materials as wood, starch, wool, silk. The substances composing these materials couldn't be crystallized from solu­tion, nor could they be isolated by distillation.

It was only in the 20th century that the scientists began thorough investigation of these materials. Having used some powerful physical instruments, an electron microscope, viscometer, X-ray diffraction apparatus, they could have revealed the polymers in all their intricacy.

Their molecules were incredibly large, the molecular weights running as high as millions of units, whereas simple organic substances such as, for instance, sugar and gasoline have molecular weights in the range of only about 50 – 500.

The giant molecules can be composed of a large number of repeating units, they being given the name "polymer" from the Greek words "poly" many and "meros" a part. Most polymers have the form of long, flexible chains. Having found out that, chemists began synthesizing artificial polymers. This has led to the establishment of industries producing synthetic fibres and numerous polymeric materials, many of which were less expensive and superior in various ways to the natural materials.

Now it's quite clear that the production of synthetic polymers is very important.

Soviet scientists work hard at this problem. It is quite clear that Soviet science will continue to create new polymers and our industry and agriculture will receive cheap new materials with valuable properties.

Notes on the Text:

1. are already in common use – уже широко распространены

2. on a large scale – в большом масштабе, количестве, широко

3. as late as the end of the 19th century – еще в конце XIX века

4. in various ways – зд. во многом

15. Answer the questions to the text:

1. Why does life depend upon organic polymers? 2. How long have people been using polymers? 3. What do organic polymers include? 4. What have modern methods of physical and chemical analyses polymeric materials uncovered? 6. When did the scientists begin thorough investigation of natural polymers? 7. What products appeared on the basis of the discovery of polymers? 8. What properties do synthetic polymers possess? 9. What are the molecules of polymers composed of?

16. Retell the text according to the following plan:

1. The importance of organic polymers.

2. The history of polymers.

3. Discoveries made by modern methods.

4. Natural organic products.

5. Synthetic polymers (their structure and properties).

6. New industry of man-made organic polymers.

17. State parts of speech the words in bold type belong to. Translate the sentences into Russian:

1. Our industry needs more and more new materials which can resist corrosion and high temperatures. 2. The need for cheap, good and beautiful materials is growing fast. 3. Phenol and acetone are needed for the manufacture of plastics. 4. New products of organic chemistry are widely used. 5. The use of this new type of polymers helps to develop new machines for the investigation of cosmic space. 6. If you listed all the properties of these new materials, you would understand their importance both in our everyday life and in research. 7. The lists with all necessary equipment have been already sent. 8. Ceramic products are known to cover a wide range of things from small ones to big constructions. 9. Semiconductor is a material whose conductivity ranges between that of conductors and non-conductors.

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