Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Chemistry A Level CIE > Chapter 16 Polymerization > Flashcards

Chapter 16 Polymerization Flashcards

You may prefer our related Brainscape-certified flashcards:
Periodic Table flashcards Chemistry 101 flashcards AP® Chemistry flashcards Organic Chemistry 101 flashcards
1
Q

Formation of Polyesters

A
  • Addition polymerisation has been covered in reactions of alkenes
    • They are made using monomers that have C-C double bonds joined together to form polymers such as (poly)ethene
  • Condensation polymerisation is another type of reaction and is used in the making of polyesters
    • A small molecule (eg. a water molecule) is lost when the monomers join together to form a polyester
    • Polyesters contain ester linkages
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

This polymer structure shows an ester functional group linking monomers together

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Formation of polyesters

A
  • A diol and a dicarboxylic acid are required to form a polyester
    • A diol contains 2 -OH groups
    • A dicarboxylic acid contains 2 COOH groups
    • When the polyester is formed, one of the -OH groups on the diol and the hydrogen atom of the -COOH are expelled as a water molecule (H2O)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Expulsion of a water molecule in this condensation polymerisation forms the polyester called Terylene (PET)

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Hydroxycarboxylic acids

A
  • A single monomer containing both of the key functional groups can also be used for making polyesters
  • These monomers are called hydroxycarboxylic acids
    • They contain an alcohol group (-OH) at one end of the molecule while the other end is capped by a carboxylic acid group (-COOH)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Both functional groups are needed to make a polyester are from the same monomer

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Amide link

A
  • Polyamides are also formed using condensation polymerisation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are required to form a polyamide

A
  • A diamine and a dicarboxylic acid
  • A diamine contains 2 -NH2 groups
  • A dicarboxylic acid contains 2 -COOH groups
  • Dioyl dichlorides can also used to react with the diamine instead of the acid
    • A dioyl chloride contains 2 -COCl groups
  • This is a more reactive monomer than dicarboxylic acid. However, a more expensive alternative
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The monomers for making polyamides (diagram)

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Nylon 6,6 is a

A
  • synthetic polyamide
  • Its monomers are 1,6-diaminohexane and hexane-1,6-dioic acid
    • The ‘6,6’ part of its name arises from the 6 carbon atoms in each of Nylon 6,6 monomers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Nylon 6,6 is a

A
  • synthetic polyamide
  • Its monomers are 1,6-diaminohexane and hexane-1,6-dioic acid
    • The ‘6,6’ part of its name arises from the 6 carbon atoms in each of Nylon 6,6 monomers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Kevlar

A
  • The polymer chains are neatly arranged with many hydrogen bonds between them
  • This results in a strong and flexible polymer material with fire resistance properties
  • These properties also lend Kevlar to a vital application in bullet-proof vests
  • The monomers used to make Kevlar
    • 1,4-diaminobenzene
    • Benzene-1,4-dicarboxylic acid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Kevlar is made using a diamine and dicarboxylic acid monomers(diagram)

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Aminocarboxylic acids

A
  • Molecules like this are called amino carboxylic acids
  • They are able to polymerise to form a structure similar to Nylon 6,6
  • They are able provides both of the function groups necessary for an amide/peptide link
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

6-aminohexanoic acid can be polymerised to make the synthetic polymer Nylon 6,6

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Protein hydrolysis

A
  • Proteins (polypeptides) can be broken down into its constituent amino acids
  • This process occurs through a hydrolysis reaction
17
Q

Making Proteins

A
  • Proteins are vital biological molecules with varying functions within the body
  • They are essentially polymers made up of amino acid monomers
  • Amino acids have an aminocarboxylic acid structure
  • Their properties are governed by a branching side group - the R group
18
Q

Different amino acids are identified by

A
  • their unique R group
  • The names of each amino acid is given using 3 letters
  • For example Glutamine is known as ‘Gln’
  • Dipeptides can be produced by polymerising 2 amino acids together
    • The amine group (-NH2) and acid group (-COOH) of each amino acid is used to polymerise with another amino acid
19
Q
  • Polypeptides are made through polymerising more than 2 amino acids together (diagram)
A
20
Q

Deducing the Repeat Unit of a Condensation Polymer

A
  • In condensation polymerisation the monomers either contain 2 of the same functional group or one single monomer has both functional groups needed for polymerisation
    • For example Diamine and dicarboxylic acid
    • Or an aminocarboxylic acid
  • When presented with 2 monomers there are steps to take in order to deduce the repeat unit of a condensation polymer
21
Q

Identifying Monomers in Condensation Polymers

A
  • When a section of polymer is presented, the monomers can be identified by considering the small molecules expelled from the monomers
  • If a water molecule is expelled, the -OH must have been from an acid group
  • The hydrogen atom may be from an amine group of a monomer.
  • If the molecule was hydrochloric acid (HCl), a dioyl chloride monomer may have been used
22
Q

Predicting Type of Polymerisation

A
  • When a set of monomers are given in an exam question, the type of polymerisation can be determined
  • Firstly, it’s important to identify the key functional groups in the monomers
23
Q

Addition polymerisation

A
  • If the monomer/s contain a C=C double bond, they will polymerise through addition polymerisation
  • The double bond can open up in order to add more monomers either side of the starting monomer
  • This type of polymerisation makes (poly)alkenes
23
Q

Addition polymerisation

A
  • If the monomer/s contain a C=C double bond, they will polymerise through addition polymerisation
  • The double bond can open up in order to add more monomers either side of the starting monomer
  • This type of polymerisation makes (poly)alkenes
24
Q

(Poly)alkenes can be produced if there are

A
  • 2 or more alkene monomers as well
  • When more than one monomer is used for addition polymerisation, the resulting product is known as a copolymer
25
Q

Monomers for condensation polymers table

A
26
Q

Identifying addition polymerisation

A
  • The polymer backbone of an addition polymer does not contain functional groups
  • The backbone of the polymer is generally a chain of carbon atoms
  • There may be sidechains branching off from the backbone
  • Some examples of side chains are benzene rings, nitrile groups (-CN) and halogen atoms (-F/-Cl/-Br/-I)
27
Q

Identifying condensation polymerisation

A
  • A condensation polymer can be identified by functional groups on the polymer backbone
  • Polyesters contain ester links and polyamides contain amide/peptide link on the backbone itself
28
Q

Hydrolysis of polyesters

A
  • Ester linkages can also be degraded through hydrolysis reactions
  • Acid hydrolysis forms the alcohols and carboxylic acids that were used to form the polyesters
29
Q

Biodegradable polymers

A
  • Both polyesters and polyamides can be broken down using hydrolysis reactions
  • This is a major advantage over the polymers produced using alkene monomers (polyalkenes)
  • When polyesters and polyamides are taken to landfill sites, they can be broken down easily and their products used for other applications
30
Q

Hydrolysis of polyamides (acidic hydrolysis)

A
  • In acidic hydrolysis, acid (such as hydrochloric acid) acts as the catalyst
    • Polyamides are heated with dilute acid
    • This reaction breaks the polyamide into carboxylic acid molecules and ammonium chloride ions
31
Q

Hydrolysis of polyamides(Alkaline hydrolysis)

A
  • The polyamide is heated with a species containing hydroxide ions (eg. sodium hydroxide)
  • This breaks the polymer into the sodium salts of its monomers (dicarboxylic acids and diamines)
  • If the poly amide link used an aminocarboxylic acid as the monomer, then a sodium salt of the original amino acid is reformed
32
Q

When polyamides are degraded by hydrolysis, carboxylic acids and amines are formed

A
33
Q

Disadvantages of photo degradability

A
  • Despite this ability being a great advantage of polyesters and polyamides, it may pose a problems when the polymers are repurposed
  • When applied to a new use, the biodegradability could give a weaker polymer
  • Breaking down polymers also poses another challenge
    • Once used, polymeric materials are taken to landfill sites where many other materials are piled on top of each other
    • This could mean that photodegradable polyesters or polyamides do not have access to UV light in order to break down naturally
34
Q

Photodegradation of Polymers

A
  • Polyesters and polyamides are biodegradable polymers for a number of reasons
  • One such reason is their ability to breakdown with the use of light
  • Carbonyl groups (C=O) along polymer chains are able to absorb energy from the Electromagnetic Spectrum
    • In particular Ultraviolet (UV) light
  • Absorbing UV light weakens the carbonyl areas of polymers and breaks them down into smaller molecules
35
Q

Recycling plants can burn used

A

plastic materials

  • The energy released from burning can be used to generate electricity
  • Burning plastics in oxygen releases carbon dioxide and water (complete combustion) which can contribute to global warming
36
Q
  • Many of the polymers in use have been produced through addition polymerisation of alkenes
A
  • The (poly)alkene chains are non-polar and saturated
  • This makes them chemically inert and therefore non-biodegradable
  • (poly)alkenes can be melted and recycled into new uses
    • However, even in the new applications, the (poly)alkenes are not biodegradable

Chemistry A Level CIE (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions