English for Materials Science I

Polymers TASK 1 . Tick the boxes that indicate a true quality of the following polymers

Thanks to stunning advances in organic chemistry, the twentieth century witnessed a major

increase in the production of goods, whose aesthetic appeal and versatility have gone

beyond any boundaries. The reason for this development lies in the fact that polymers with

their special carbon structure exhibit properties that triggered scientific curiosity and

inspired products such as nylon, plastic bags, video tapes or even shatter-proof aircraft

windows.

Polymers are compounds of high molecular weight formed by the chemical

combination of two or more molecules of the same kind held together by normal valency

bonds. Polymers can be divided into two broad categories: natural and synthetic. Naturally

occurring polymers cannot only be found in wood, wool or cotton but also in cellulose, a

plant polymer made of the monomer of glucose. A protein such as keratin is also a natural

polymer which we find in our hair, skin and fingernails. Yet, the best example of natural

polymers is that of natural rubber, which we often use in the form of ropes due to its

structural strength. Its property to stretch and revert back to its original shape renders it

essential in the chemical industry.

The chemical industry, however, has come a long way since its reliance on natural polymers.

Advances in the chemical laboratory led to the

widespread development and use of even more diverse

products made of synthetic polymers. Along with the

growth of the oil industry, industrial polymers paved

the way for the production of synthetic fibres,

elastomers and plastics.

Generally, synthetic polymers can be categorised in terms of their physical and

chemical qualities and structure, their use, degree of polymerisation and their processing:

Crystalline and amorphous, branched, linear and cross-linked, thermoplastic and

thermosetting are only a small sample of the numerous divisions of polymers.

Crystalline polymers are rigid and they have a symmetrical structure, a relatively

regular order and arrangement, such as that of a crystal lattice. Their crystallinity makes the

materials strong and it also makes them brittle. A well-known crystalline polymer is PET.

Some polymers such as nylon can be both crystalline and amorphous. Amorphous polymers

have a random order and irregular arrangement on the molecular scale. They are also

endowed with toughness which means that they can absorb stress, they bend but they do

not break. They have varied commercial applications as adhesives, sealants and electronic

materials. The degree of crystallinity of polymers may depend on their structure, their

molecular weight, stereochemistry or heat. It has been noticed, for instance, that the more

heat you supply the higher the viscosity of amorphous materials, whereas crystalline objects

are more likely to retain their rigidity.

Polymers have a linear, branched or a cross-linked arrangement. Linear polymers are

monomers joined together in a linear arrangement like a straight chain. Branched polymers

have a linear arrangement with a few side-branches. Cross-linked polymers consist of a

tangled network of straight chains that cross-link.

The structure of polymers determines chemical behaviour such as solubility, solvent

permeability and thermal stability. In terms of solubility, solvents may penetrate and

dissolve linear or branched polymers. Cross-linked polymers, however, are insoluble so they

do not allow dissolution to occur. When it comes to thermal stability and elasticity, linear

and branched polymers may become viscous under certain temperatures and pressure,

whereas cross-linked polymers are resistant to elevated temperatures and they do not melt.

Depending on how they react to the application of heat, polymers can also be

classified as thermosetting or thermoplastics. Thermoplastic polymers such as nylon consist

of a large tangle of linear or branched molecules held together by intermolecular

attractions. When heated, they soften and can be moulded into a desired shape repeatedly.

On the other hand, thermosets are comprised of cross-linked polymers, which, when

heated, do not soften but stiffen, harden and retain their rigid structure.

Based on their use, synthetic polymers are divided into plastics, elastomers and

fibres. Although they derive their name from thermoplastics, plastics display qualities that

apply to both thermosets and thermoplastics. They do not break down, they do not rot and

they are not biodegradable. They can be either soft or tough, resilient or pliable, building

materials or superconductors.

Fibres, such as nylon, are thermoplastics held together in a linear arrangement and

derived from either plastics or elastomers. They often appear in textiles. Elastomers become

mainly cross-linked after mechanical processing such as vulcanisation. An example of an

elastomer is rubber which shows great strength and stretchability but has a low degree of

crystallinity. They are known for their tensile strength, that is their ability to stretch a long

distance, and they bounce back without suffering a great deal of deformation.

a. Read the text and answer the following questions:

1. Crystalline materials are strong, amorphous ones are tough. What is the difference

between strength and toughness?

2. How are polymers classified based on their structure?

3. How are polymers classified based on their thermal behaviour?

4. How do the structural properties interact with that of thermal behaviour?

5. What other qualities are affected by the polymer structure and how?

6. How are polymers classified based on their use?

7. Which polymer products put pressure on the environment and why?

8. What is the most well-known feature of elastomers?

b. Read the statements and say whether they are true (T) or false (F):

1. Polymer products may be versatile but they are not appealing.

2. Cotton, cellulose and rubber are examples of synthetic polymers.

3. Synthetic polymer products are only derived from petroleum.

4. Nylons are thermoplastic polymers with a crystalline structure.

5. Crystalline polymers are adhesive.

6. Amorphous polymers are viscous.

7. Thermosetting polymers cannot be reshaped.

8. Thermoplastics are those with a branched or linear structure.

9. Linear polymers are insoluble but branched and cross-linked are soluble.

10. Plastic is thermoplastic, hence its name.

11. The tensile strength measures the energy absorbed by an object before it breaks

and its resistance to deformation.

12. Vulcanisation involves mechanical processing of polymers.

1. Find words from the text that mean the following:

(paragr.1) experienced limits

ability to do

different things show

(paragr.2) turn back to its former place made

(paragr.3) the act of relying on the development

blazed the trail for varied

(paragr.5) fragile keep

stiff; inflexible sticky substances

quality of being semi-fluid irregular

sustaining tension without breaking

(paragr.6) allowing passage of e.g. fluids to pass through

disintegration expressing opposition

(paragr.7) twisted in a confused mass work into shape

(paragr.8) springing back to its former position flexible

2. Complete the. The words are adjectives found in the text. What's the horizontal acrostic

word formed?

1. of different sorts; diverse

2. of business practices; buying and selling

3. uneven; varying or unequal

4. of the natural features of the material

5. that cannot be dissolved

engaged in manufacture or production

6. not natural; artificial

3. Find these words in the text and choose the right meaning:

Thermosetting a. it cannot be remoulded without the application of heat

b. it does not soften when heated

Thermoplastic a. it can be heated but not reshaped

b. it does not harden after the heating process

Branched a. it has branch chains coming off its backbone chain in an irregular

manner.

b. its backbone chains are bonded together to form a linear

structure.

Cross-linked a. its backbone chains are bonded together to form a larger, non-

linear structure, which resembles a network.

b. a sequence of atoms to which additional atoms are attached

Fibre a. linear thermoplastic used to make fabric

b. branched thermoplastic used to make fabric

Elastomers a. Cross-linked thermosettings with increased stretchability

b. thermoplastic polymers that exhibit extensibility and elastic

recovery.

Listen to a part of a lecture based on Smart polymers match relevant information:

1. Smart polymers or stimuli-responsive polymers

2. Slight change in humidity, pH, the intensity of light or an electrical or magnetic field

3. Slight changes in pH, ionic strength or temperature

4. Once that slight change occurs

A. may change their conformation, adhesiveness or water retention properties

B. high-performance polymers responsive to their environment

C. there is complete uniformity throughout the polymer

D. induce greater change in the polymer’s properties such as conductivity and water permeability

4. Complete the sentences with an appropriate word. Not all the words need to be used.

divided

composed

substitutes

suited

known

superior

polymers

foremost

proceed

derived

tangled

renders

lattice

elevated

penetrate

resilient

pliable

exhibit

The properties of rubber, like those of other ..................., are determined by chemical

and physical structure.

Plastics were produced as ....................for wood and metal.

The symmetrical structure, formed by the particles in a crystal, is called

crystal...............

Plastics are called thermoplastics after the ....................member of the polymer class.

The theory of polymer crystallinity has been ..............from Herman Mark.

At .....................temperature, thermoplastic polymers become ............... and elastic.

Synthetic rubbers have properties ........................to those of natural products.

Vegetable fibre is .......................of cellulose.

Cross-linked polymers are ....................in a network. They are rigid

and .....................and they don not allow any solvent to .......................and dissolve

them.

Amorphous polymers ....................properties such as that of viscosity

which .................... them useful as adhesives and sealants.

Gerund or infinitive?

Which of the following functions match the examples?

1. Verbs that are followed only by -ing (gerund)

2. Verbs that are followed only by the infinitive with to

3. Verbs that are followed by the infinitive without to

4. Gerund as a noun, either as subject or object.

5. Infinitive that shows purpose.

6. Adjectives followed by an infinitive

7. Expressions followed by a gerund

8. Prepositions are followed by gerunds

9. Words that are followed by either but their meaning changes.

10. Relative pronouns are followed by infinitive

a) For an undergraduate student, it is difficult to grasp polymerisation processes.

b) There is no point in using protective equipment when we are not aware of possible

dangers in general.

c) He wondered which experiment to conduct.

d) We need to consider recycling non-biodegradable plastics.

e) Researchers actually have started supporting /to support the latter view.

f) When it comes to classifying polymers, an endless list emerges.

g) He needn't hand in the report today.

h) My professor insists on having made an error and intends to replicate the

experiment.

i) Most thermoplastics are too tough to break.

j) Polymerizing not only one monomer but a mixture of two or three gives us

copolymers.

k) The committee meant to discuss the matter thoroughly tomorrow. Does that mean

changing plans?

l) To cut a long story short, the molecular weight of polymers continues to

increase/increasing.

Complete the following sentences with either gerund or infinitive:

a) They suggested ......................(postpone) the date of the exam since most students

would be missing.

b) P.V.C is not supposed ................(be) used in a plasticized form.

c) He admitted to .........................(make) a mistake.

d) They will never forget......................... (persuade) their professor ..................(make)

amendments for them.

e) My colleague is very diplomatic and tends ....................(evade) ................(answer)

any tricky questions.

f) Scientists are obliged ..................(comply) with European rules on recycling.

g) A growing number of companies in Britain specialise in .............(recycle) plastics.

h) It's worth ...............(mention) that incineration of plastics allows even more carbon

dioxide ...............(be) released into the atmosphere.

i) Depolymerisation requires....................... (crack) polymers that have lost their

qualities.

Wordiness 2

1. In a scientific paper, wordiness, a writer's tendency to say something using more words

than required, can often obscure the message. Read the examples and match them with

their interpretation.

a. It is a process that....

This process...

b. There are two hypotheses that can be...

Two hypotheses can be...

c. These applications are diverse at the

present time .....diverse now.

d. The figures are in agreement.

The figures agree.

e. As already stated,...

Helpful Writing Tip

-Start a sentence directly with the subject without using 'it' or 'there is', followed by a

relative clause.

-Use one or no words rather than a wordy phrase.

2. Read the text carefully and look for any wordy phrases. How many are there?

3. Phrases and words that should not be used in scientific papers are presented in the table.

Choose the right alternative: because, apparently, although, possibly, after, blue, several,

more, a few, large, if, hexagonal, reported, clearly, (omit).

it is possible that reported in the

literature

it has been

demonstrated that

due to the fact that

It would appear that hexagonal in shape it may be added that owing to the fact that

it is clear that large in size it's worth mentioning

that

in the view of the fact

that

if it is hypothesised based on the fact that a great/ small number

of

in spite of/ despite the

fact that

if we suppose that more in number subsequent to blue in colour

4. Rewrite the following sentences so that they are less wordy.

a. All solvents cause thermoplastics to dissolve.

b. Thermosets do not allow dissolution to occur.

c. Polymerisation will produce an increase in the molecular weight of polymers.

d. Herman Mark conducted an analysis on the theory of polymer crystallinity.

e. Combatibilisers are used in order to mix polymers of different chemical properties

into homogeneous compounds.

f. High temperatures are employed to cause viscosity and elasticity in products.

g. PET is known to be one of the hardest plastics.

Since incineration is not a safe option, scientists are limited to recycling plastics.

Listen to a part of a lecture based on the physical properties and uses of common plastic

products. Complete the missing information:

Bottom of plastic bottle indicating recycling potential

Plastics Physical properties Products

P.E. 1...........................

2...........................

3. ..........................

4. ..........................

5. ..........................

P.P. 6. .......................... 7. ..........................

8. ..........................

9. ..........................

10. ................ 11...........................

12..........................

13..........................

14..........................

aircraft windows

camera lenses

P.E.T. electrical insulator 15.bottles

16.

Nylon 17. ..........................

18. ..........................

19. ..........................

20. ..........................

h.