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iGCSE chemistry Section 5 lesson 3. Content. The iGCSE Chemistry course. Section 1 Principles of Chemistry Section 2 Chemistry of the Elements Section 3 Organic Chemistry Section 4 Physical Chemistry Section 5 Chemistry in Society. Content. Section 5
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Content The iGCSE Chemistry course Section 1 Principles of Chemistry Section 2 Chemistry of the Elements Section 3 Organic Chemistry Section 4 Physical Chemistry Section 5 Chemistry in Society
Content Section 5 Chemistry in industry • Extraction and uses of metals • Crude oil • Synthetic polymers • The industrial manufacture of chemicals
Lesson 3 c) Synthetic polymers c) Synthetic polymers 5.15 understand that an addition polymer is formed by joining up many small molecules called monomers 5.16 draw the repeat unit of addition polymers, including poly(ethene), poly(propene) and poly(chloroethene) 5.17 deduce the structure of a monomer from the repeat unit of an addition polymer 5.18 describe some uses for polymers, including poly(ethene), poly(propene) and poly(chloroethene) 5.19 explain that addition polymers are hard to dispose of as their inertness means that they do not easily biodegrade 5.20 understand that some polymers, such as nylon, form by a different process called condensation polymerisation 5.21 understand that condensation polymerisation produces a small molecule, such as water, as well as the polymer.
The Monomer Do you remember ethene?
The Monomer Do you remember ethene? Alkene C2H4
The Monomer Do you remember ethene? Alkene C2H4 Unsaturated hydrocarbon because it has a double bond
The Monomer Can be produced by the cracking of crude oil products Do you remember ethene? Alkene C2H4 Unsaturated hydrocarbon because it has a double bond
The Monomer Can be produced by the cracking of crude oil products Do you remember ethene? Individual ethene molecules can join together to form longer chain molecules called POLYMERS Alkene C2H4 Unsaturated hydrocarbon because it has a double bond
Polymerization The process of joining single monomers together to form longer chain polymers is known as polymerization.
Polymerization The process of joining single monomers together to form longer chain polymers is known as polymerization. Pressure + Catalyst
Polymerization The process of joining single monomers together to form longer chain polymers is known as polymerization. Pressure Catalyst +
Polymerization The process of joining single monomers together to form longer chain polymers is known as polymerization. Pressure Catalyst + Polyethene molecule (or “polythene”) Single ethene molecules
Polymerization The process of joining single monomers together to form longer chain polymers is known as polymerization. Polyethene is a wax-like solid with an average relative molecular mass of about 30,000 – 50,000 Pressure Catalyst + Polyethene molecule (or “polythene”) Single ethene molecules
Polymerization This process is known as addition polymerization because the polymer has the same basic formula as the monomer.
Polymerization This process is known as addition polymerization because the polymer has the same basic formula as the monomer. Polyethene is one of a large group of synthetic substances that we refer to as PLASTICS.
PLASTICS - advantages Easily shaped and moulded, and can be extruded, injection moulded and vacuum formed
PLASTICS - advantages Easily shaped and moulded, and can be extruded, injection moulded and vacuum formed They are relatively inexpensive, being produced as a by-product of oil refining.
PLASTICS - advantages Easily shaped and moulded, and can be extruded, injection moulded and vacuum formed They are relatively inexpensive, being produced as a by-product of oil refining. They are durable, and do not rust, corrode or decay.
PLASTICS - advantages Easily shaped and moulded, and can be extruded, injection moulded and vacuum formed They are relatively inexpensive, being produced as a by-product of oil refining. They are durable, and do not rust, corrode or decay. They are lighter than steel, wood or stone.
PLASTICS - advantages Easily shaped and moulded, and can be extruded, injection moulded and vacuum formed They are relatively inexpensive, being produced as a by-product of oil refining. They are durable, and do not rust, corrode or decay. They are lighter than steel, wood or stone. They are thermal and electrical insulators.
PLASTICS - disadvantages They are not biodegradable. This means that they do not decay naturally
PLASTICS - disadvantages They are not biodegradable. This means that they do not decap naturally Many plastics produce poisonous fumes when they burn.
Other examples of addition polymers Propene C3H6 Polypropene or polypropylene Use: washing-up bowls
Other examples of addition polymers Chloroethene (Vinyl chloride) C2H3Cl Polychloroethene or PVC Use: waterproof material
So that was addition polymerization. What’s all this I hear about condensation polymerization? CH3 C = C H
So that was addition polymerization. What’s all this I hear about condensation polymerization? CH3 C = C H What’s a condensation reaction?
Condensation Reaction: “Two molecules combine with the loss of a smaller molecule, which may be water”.
Condensation Reaction: “Two molecules combine with the loss of a smaller molecule, which may be water”. The polymer does not have the same empirical formula as the monomers.
For example, nylon is made by condensation polymerization. Hexane-1,6-diamine Adipyl chloride
For example, nylon is made by condensation polymerization. Rotate Nylon Hexane-1,6-diamine Adipyl chloride
For example, nylon is made by condensation polymerization. Rotate Nylon Hexane-1,6-diamine + adipyl chloride nylon + hydrogen chloride Hexane-1,6-diamine Adipyl chloride
End of Section 5 Lesson 3 In this lesson we have covered: The monomer Addition polymerization Condensation polymerization
H CH3 Cl H Cl C = C C C C C H H Cl H H H H C = C H H
