A polyester is a condensation polymer in which monomers are linked by ester bonds (-COO-), formed from a diol and a dicarboxylic acid (or a hydroxycarboxylic acid).

What two types of monomer are required to form a polyester by condensation polymerisation?

A diol (containing two -OH groups) and a dicarboxylic acid (containing two -COOH groups). A small molecule of water is eliminated each time a new ester link forms.

True or False? Polyethylene terephthalate (PET) is a polyester formed by condensation polymerisation.

True. PET (also known as Terylene) is formed from the condensation polymerisation of ethane-1,2-diol and benzene-1,4-dicarboxylic acid, with water eliminated at each ester link.

What is a hydroxycarboxylic acid and how can it form a polyester?

A hydroxycarboxylic acid contains both an -OH group and a -COOH group on the same molecule. It can self-condense to form a polyester, with a water molecule eliminated at each ester link.

In polyester formation, the .......... group on the dicarboxylic acid and the .......... from the diol are expelled as a water molecule.

In polyester formation, the -OH group on the dicarboxylic acid and the H from the diol are expelled as a water molecule.

True or False? In addition polymerisation, a small molecule is eliminated when monomers join together.

False. In addition polymerisation, no small molecule is expelled. It is condensation polymerisation in which a small molecule such as water or HCl is eliminated.

What functional group forms the linkage between monomers in a polyester?

The ester link (-COO-) joins the monomers in a polyester. It is formed by the reaction between the -COOH group of one monomer and the -OH group of the other.

Define condensation polymerisation .

A condensation polymerisation is a type of polymerisation in which monomers join together and a small molecule (such as H 2 O or HCl) is eliminated with each new bond formed.

Polyesters can also be formed from a single monomer called a .......... , which contains both an -OH group and a .......... group.

Polyesters can also be formed from a single monomer called a hydroxycarboxylic acid , which contains both an -OH group and a -COOH group.

A polyamide is a condensation polymer in which monomers are linked by amide (peptide) bonds (-CONH-), formed from a diamine and a dicarboxylic acid or dioyl chloride.

What are the monomers used to make nylon 6,6?

Nylon 6,6 is made from 1,6-diaminohexane and hexane-1,6-dioic acid . The '6,6' reflects the 6 carbon atoms in each monomer.

True or False? A dioyl chloride is a less reactive but cheaper alternative to a dicarboxylic acid for making polyamides.

False. Dioyl chlorides are more reactive than dicarboxylic acids. They are a more expensive alternative, but the increased reactivity makes the reaction proceed more readily.

What properties make Kevlar suitable for use in bullet-proof vests?

Kevlar is strong and flexible with fire-resistant properties. Its polymer chains are neatly arranged with many hydrogen bonds between them, giving it high tensile strength.

Nylon 6 can also be formed from the single monomer .......... , which contains both an amine group and a carboxylic acid group on the same molecule.

Nylon 6 can also be formed from the single monomer 6-aminohexanoic acid , which contains both an amine group and a carboxylic acid group on the same molecule.

True or False? Kevlar is formed from 1,4-diaminobenzene and benzene-1,4-dicarboxylic acid.

True. These two monomers condense to form Kevlar via amide links. A dioyl chloride (benzene-1,4-dioyl chloride) can be used in place of the dicarboxylic acid.

What small molecule is expelled when a diamine reacts with a dicarboxylic acid to form a polyamide?

Water (H 2 O) is expelled. The -NH 2 group of the diamine reacts with the -COOH group of the acid, eliminating water and forming the amide link.

An amide link is the -CONH- functional group that joins monomers in a polyamide. It is also called a peptide link when it forms in biological polymers such as proteins.

When a dioyl chloride reacts with a diamine to form a polyamide, the small molecule expelled is .......... . When a dicarboxylic acid reacts with a diamine, the small molecule expelled is .......... .

When a dioyl chloride reacts with a diamine to form a polyamide, the small molecule expelled is HCl . When a dicarboxylic acid reacts with a diamine, the small molecule expelled is H 2 O .

A repeat unit is the smallest structural fragment that repeats throughout a polymer chain. It is enclosed in brackets with a subscript n to represent the repeating nature of the polymer.

How can you identify whether a polymer was made by addition or condensation polymerisation from its structure?

If the backbone consists only of carbon atoms with no functional groups, it is an addition polymer . If the backbone contains ester links (-COO-) or amide links (-CONH-), it is a condensation polymer .

True or False? A condensation polymer made from a dioyl chloride and a diamine expels water as the small molecule.

False. When a dioyl chloride reacts with a diamine, the small molecule expelled is HCl (the Cl from the chloride and H from the amine). Water is expelled when a dicarboxylic acid is used instead.

How do you identify the monomers from a section of a condensation polymer?

Locate the linking groups (ester or amide bonds). Consider which small molecule was expelled (H 2 O or HCl). Split the chain at each link and add back the expelled atoms to reconstruct the original monomer structures.

A polyester contains .......... links in the backbone. A polyamide contains .......... links in the backbone.

A polyester contains ester (-COO-) links in the backbone. A polyamide contains amide (-CONH-) links in the backbone.

True or False? An aminocarboxylic acid can act as both monomers needed for condensation polymerisation on its own.

True. An aminocarboxylic acid has an -NH 2 group and a -COOH group on the same molecule. These two groups can react with each other, so it can self-polymerise to form a polyamide.

What does the subscript n represent in the structural formula of a polymer repeat unit?

The subscript n indicates the number of repeat units in the polymer chain. It shows that the enclosed structural unit repeats many times throughout the polymer.

Define aminocarboxylic acid .

An aminocarboxylic acid is a monomer that contains both an -NH 2 group and a -COOH group, allowing it to undergo self-condensation polymerisation to form a polyamide.

In condensation polymerisation, when -OH from an acid reacts with -H from an amine, the small molecule lost is .......... . When -Cl from a dioyl chloride reacts with -H from an amine, the small molecule lost is .......... .

In condensation polymerisation, when -OH from an acid reacts with -H from an amine, the small molecule lost is H 2 O . When -Cl from a dioyl chloride reacts with -H from an amine, the small molecule lost is HCl .

A LevelChemistryCambridge (CIE)Flashcards35. PolymerisationCondensation Polymerisation

Condensation Polymerisation (Cambridge (CIE) A Level Chemistry): Flashcards

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FrontFormation of Polyesters
Define polyester.

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Define polyester.
A polyester is a condensation polymer in which monomers are linked by ester bonds (-COO-), formed from a diol and a dicarboxylic acid (or a hydroxycarboxylic acid).
What two types of monomer are required to form a polyester by condensation polymerisation?
A diol (containing two -OH groups) and a dicarboxylic acid (containing two -COOH groups). A small molecule of water is eliminated each time a new ester link forms.
True or False?
Polyethylene terephthalate (PET) is a polyester formed by condensation polymerisation.
True.
PET (also known as Terylene) is formed from the condensation polymerisation of ethane-1,2-diol and benzene-1,4-dicarboxylic acid, with water eliminated at each ester link.
What is a hydroxycarboxylic acid and how can it form a polyester?
A hydroxycarboxylic acid contains both an -OH group and a -COOH group on the same molecule. It can self-condense to form a polyester, with a water molecule eliminated at each ester link.
In polyester formation, the .......... group on the dicarboxylic acid and the .......... from the diol are expelled as a water molecule.
In polyester formation, the -OH group on the dicarboxylic acid and the H from the diol are expelled as a water molecule.
True or False?
In addition polymerisation, a small molecule is eliminated when monomers join together.
False.
In addition polymerisation, no small molecule is expelled. It is condensation polymerisation in which a small molecule such as water or HCl is eliminated.
What functional group forms the linkage between monomers in a polyester?
The ester link (-COO-) joins the monomers in a polyester. It is formed by the reaction between the -COOH group of one monomer and the -OH group of the other.
Define condensation polymerisation.
A condensation polymerisation is a type of polymerisation in which monomers join together and a small molecule (such as H₂O or HCl) is eliminated with each new bond formed.
Polyesters can also be formed from a single monomer called a .......... , which contains both an -OH group and a .......... group.
Polyesters can also be formed from a single monomer called a hydroxycarboxylic acid, which contains both an -OH group and a -COOH group.
Define polyamide.
A polyamide is a condensation polymer in which monomers are linked by amide (peptide) bonds (-CONH-), formed from a diamine and a dicarboxylic acid or dioyl chloride.
What are the monomers used to make nylon 6,6?
Nylon 6,6 is made from 1,6-diaminohexane and hexane-1,6-dioic acid. The '6,6' reflects the 6 carbon atoms in each monomer.
True or False?
A dioyl chloride is a less reactive but cheaper alternative to a dicarboxylic acid for making polyamides.
False.
Dioyl chlorides are more reactive than dicarboxylic acids. They are a more expensive alternative, but the increased reactivity makes the reaction proceed more readily.
What properties make Kevlar suitable for use in bullet-proof vests?
Kevlar is strong and flexible with fire-resistant properties. Its polymer chains are neatly arranged with many hydrogen bonds between them, giving it high tensile strength.
Nylon 6 can also be formed from the single monomer .......... , which contains both an amine group and a carboxylic acid group on the same molecule.
Nylon 6 can also be formed from the single monomer 6-aminohexanoic acid, which contains both an amine group and a carboxylic acid group on the same molecule.
True or False?
Kevlar is formed from 1,4-diaminobenzene and benzene-1,4-dicarboxylic acid.
True.
These two monomers condense to form Kevlar via amide links. A dioyl chloride (benzene-1,4-dioyl chloride) can be used in place of the dicarboxylic acid.
What small molecule is expelled when a diamine reacts with a dicarboxylic acid to form a polyamide?
Water (H₂O) is expelled. The -NH₂ group of the diamine reacts with the -COOH group of the acid, eliminating water and forming the amide link.
Define amide link.
An amide link is the -CONH- functional group that joins monomers in a polyamide. It is also called a peptide link when it forms in biological polymers such as proteins.
When a dioyl chloride reacts with a diamine to form a polyamide, the small molecule expelled is ........... When a dicarboxylic acid reacts with a diamine, the small molecule expelled is .......... .
When a dioyl chloride reacts with a diamine to form a polyamide, the small molecule expelled is HCl. When a dicarboxylic acid reacts with a diamine, the small molecule expelled is H₂O.
Define repeat unit.
A repeat unit is the smallest structural fragment that repeats throughout a polymer chain. It is enclosed in brackets with a subscript n to represent the repeating nature of the polymer.
How can you identify whether a polymer was made by addition or condensation polymerisation from its structure?
If the backbone consists only of carbon atoms with no functional groups, it is an addition polymer. If the backbone contains ester links (-COO-) or amide links (-CONH-), it is a condensation polymer.
True or False?
A condensation polymer made from a dioyl chloride and a diamine expels water as the small molecule.
False.
When a dioyl chloride reacts with a diamine, the small molecule expelled is HCl (the Cl from the chloride and H from the amine). Water is expelled when a dicarboxylic acid is used instead.
How do you identify the monomers from a section of a condensation polymer?
Locate the linking groups (ester or amide bonds). Consider which small molecule was expelled (H₂O or HCl). Split the chain at each link and add back the expelled atoms to reconstruct the original monomer structures.
A polyester contains .......... links in the backbone. A polyamide contains .......... links in the backbone.
A polyester contains ester (-COO-) links in the backbone. A polyamide contains amide (-CONH-) links in the backbone.
True or False?
An aminocarboxylic acid can act as both monomers needed for condensation polymerisation on its own.
True.
An aminocarboxylic acid has an -NH₂ group and a -COOH group on the same molecule. These two groups can react with each other, so it can self-polymerise to form a polyamide.
What does the subscript n represent in the structural formula of a polymer repeat unit?
The subscript n indicates the number of repeat units in the polymer chain. It shows that the enclosed structural unit repeats many times throughout the polymer.
Define aminocarboxylic acid.
An aminocarboxylic acid is a monomer that contains both an -NH₂ group and a -COOH group, allowing it to undergo self-condensation polymerisation to form a polyamide.
In condensation polymerisation, when -OH from an acid reacts with -H from an amine, the small molecule lost is ........... When -Cl from a dioyl chloride reacts with -H from an amine, the small molecule lost is ...........
In condensation polymerisation, when -OH from an acid reacts with -H from an amine, the small molecule lost is H₂O. When -Cl from a dioyl chloride reacts with -H from an amine, the small molecule lost is HCl.

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