READING
The Essentials book pg 278, 287- 290
Q6.10
 discuss the advantages and disadvantages of using polymers,
 define rigidity and describe how bonding between polymer chains affects rigidity,
 define the terms thermoplastic and thermoset polymers,
 describe how heating affects theroplastics and thermoset polymers,
 describe how the affect of heat can determine the ease of recycling of a thermoplastic and a thermoset polymer.
The production of synthetic polymers presents the opportunity to manufacture materials with a diverse range of properties.
Discuss the advantages and disadvantages of synthetic polymers.
Organic polymers can have different properties, such as rigidity, depending upon the monomers and the degree of cross-linking between chains.
Heat affects thermoplastic and thermoset polymers differently.
Describe the effect on rigidity of increasing the number of primary and secondary bonds between polymer chains.
Describe the effects of heating on thermoplastic and thermoset polymers, and the consequent difference in ease of recycling.
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:
Organic polymers can be derived from compounds in petroleum and by-products made in its processing.
The production of synthetic polymers presents the opportunity to manufacture a range of materials with a diverse range of properties.
Organic polymers can have different properties, such as rigidity, depending on the monomers and the degree of cross-linking between the chains.
Heat affects thermoplastics and thermoset polymers differently.
Naturally occurring polymers like cotton, silk and wool, have been put to use for thousands of years.
Synthetic polymers, however, are mainly a development of the last 100 years. Polymers are used widely and it would be difficult to imagine our lifestyle without them.
The widespread use of polymers can be attributed to the vast range of properties they exhibit.
You are required to be able to describe examples of the relationships between the structure and properties of polymers.
As well as the benefits brought about by the development of polymers, there are also problems associated with their extensive use.
You need to be able to describe both advantages and disadvantages of the general use of polymers.
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Some of the important properties of polymers are:
Flexibility , Rigidity , Elasticity , Hardness , Brittleness
These properties will depend on ________________________________________________________________
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Dispersion forces
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Hydrogen bonding
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Covalent bonding
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There are two main types of polymers:
Thermoplastics :
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Thermoset polymers :
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Advantages Disadvantages
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The following is a part of the structure of starch, a condensation polymer. a) Circle two groups on the structure of starch that may be responsible for hydrogen bonding between starch chains. b) Describe three properties these hydrogen bonds would give the starch molecule.
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______________________________________________________________________________________ c) Draw brackets around a repeating unit on the section of starch shown. d) Starch is a condensation polymer . Explain the meaning of this term.
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______________________________________________________________________________________ e) The hydroxyl groups on CH
2
OH in the starch side-chain can be converted into ethanoate, ester groups. i Name a suitable chemical compound that could be used to react with this CH convert it to starch ethanoate.
2
OH group on starch to ii iii
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Describe how this reaction and conversion of starch into starch ethanoate may change the original properties of starch.
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Explain these differences in properties.
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The key ideas here are being able to:
Describe the effect on rigidity of increasing the number of primary and secondary interactions (bonds) between polymer chains.
Describe the effects of heating on thermoplastic and thermoset polymers, and the consequent difference in ease of recycling.
NOTES LEARNING
Polymers can be divided according to their plastic properties.
Name the two types of polymers.
Describe what happens when thermoplastics are heated?
What is the consequence of this?
Draw a diagram of a typical thermoplastic.
Describe what happens when thermoset polymer is heated?
What is the consequence of this?
Draw a diagram of a thermoset polymer.
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The presence of bonding between polymer chains will greatly affect the rigidity of a plastic.
Bonding between polymer chains could be: dispersion forces – hydrogen bonding – primary covalent bonds –
As the number and strength of bonds between polymer chains increases, list four properties that also change.
Draw a diagram of a polymer with no cross-links eg HDPE
Draw a diagram of a polymer with no crosslinks, but has side chains eg LDPE
Draw a diagram of a polymer with cross-links rigidity hardness elasticity softness flexible
2.
3.
1.
4.
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Describe what is meant when we talk about polymer cross-links ?
Which of these “bonds” would be strongest?
Which of these “bonds” would be weakest?
Complete the table:
Property Polymer with crosslinks-YES/NO

(read the information in your notes.)
List six advantages .
List six disadvantages . 1
6
5
4
3
2
1
5
4
6
3
2
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1 The following diagram represents three different types of polymers.
Polymer A
Polymer C
Polymer B a) Which polymer would be the most flexible? _________________________________ b) Explain which of these polymers would be the least dense.
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_______________________________________________________________________________ c) Describe the effect of heating on Polymer C.
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_______________________________________________________________________________ d) Classify Polymer A as being thermoset or thermoplastic. ________________________________ e) Explain which of the three polymer types would be easiest to recycle.
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3
2 A section of the structure of polystyrene is shown below: a) Draw the structural formula of the monomer used to make polystyrene. b) Polystyrene is an addition polymer. Explain this term.
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The polymer below was developed to be used in the optical industry. a) Bracket the repeating unit in the polymer. b) One of the monomers used to make the polymer has the formula HO(CH
2
)
2
OH.
Draw the structural formula of the other monomer used to make this polymer. c) The polymer was found to absorb water and swell and hence was unsuitable for use in the optical industry.
Explain how this polymer is able to absorb water and swell.
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