Notes and commentary

1. plant tissues – тканини рослин

2. numerous products of ancient and modern industry – багаточисленні вироби стародавньої та сучасної промисловості

3. are either entirely or substantially polymeric – є полімерними повністю або в значній мірі

4. low-molecular-weight units - одиниці з низькою молекулярною вагою

Vocabulary

ancient - стародавній, первісний arrangement - розташування body - тіло consist of- складатися з differ- різнитися entirely- повністю

essential - істотний human- людський percentage- відсотковий possess - володіти proteins - білки with regard to - по відношенню

Exercises

1. Answer the questions.

1. What do human body, animal and plant tissues consist of?

2. What polymeric products do you know?

3. What inorganic polymers do you know?

4. What is common for all these substances?

5. What is a polymer?

6. What is an isomeric polymer?

7. What is a homopolymer?

8. What are copolymers?

2. Match English word combinations with their Ukrainian equivalents.

1. organic nature а. єдиний вид

2. macromolecular materials b. спільна риса

3. common feature c. ізомерні полімери

4. isomeric polymers d. органічна природа

5. single type e. макромолекулярні

матеріали

3. Match Russian word combinations with their English equivalents.

1. різні види a. monomeric units

2. мономірні одиниці b. different types

3. сучасна промисловість c. inorganic polymers

4. неорганічні полімери d. modern industry

3. Retell text using questions from Ex. 1 as a plan.

5. Read, translate and do the tasks.

1. Write the symbols for the following materials: silica and feldspar, magnesium, gold, silver.

2. Write chemical formulas for the following products of industry: glass, rubber, paper.

Some applications of polymers

In many cases the marketability of a polymer is due to the theologically complex behavior of the material. An example can be found in the compounding of materials for coating of surfaces. The non-newtonian behaviour of paints is an important factor in determining the "brushability" of paint. Interesting tests have been devised to measure this quality in the laboratory. One wishes to have a paint that will not show brush marks after drying; on the other hand, if the paint is too thin it will not adequately cover a surface.

Similarly, the art of paper coating is highly dependent on the rheology of the coating material. In conventional coating applications the coating "colour", as it is called, is subjected to extreme variations of high and low shearing.

The petroleum industry uses large quantities of "drilling muds" to lubricate the drill bit and to carry rock chips out of the hole during drilling of oil wells. It is important to have muds which exhibit low viscosity under sharing but which are very thick at rest, thus preventing rapid settling of chips when the drilling unit is not in operation.

Further examples can be given almost without limit. We note that most foodstuffs are non-newtonian. This is important in respect both to food processing and to the preparation of acceptable natural food substitutes.