C11 Polymers Flashcards
What is polymerisation?
The reaction in which small monomer units join together to form large molecules called polymers.
What are the two types of polymerisation?
Addition and Condensation
Addition polymerisation
- Process in which identical alkene monomers are added together to form a polymer via an addition reaction.
- The double bond in the alkene molecules open up so that they can join together to form a large polymer molecule.
- The reaction is carried out under pressure in the presence of a catalyst.
What is a monomer?
- The small molecules that join together to form the large polymer chains
- They are alkenes, therefore they contain a double bond
Give two uses of poly(ethene)
Plastics: drink bottles, carrier bags
Condensation polymerisation
Monomers join together and remove a small molecule, such as water
- Esters are formed when a carboxylic acid reacts with an alcohol in the presence of a catalyst
- This is a condensation reaction because water is also produced
What do you need to make an ester?
Carboxylic acid and alcohol
Why is this process called a condensation reaction?
Forms a product of water
Uses of polyester
- Clothes
- Plastic bottles
- Fibres
Condensation polymerisation - functional groups
- To form a long chain, each monomer must have two functional groups, one at each end of the molecule
- Remove H from both alcohol functional groups
- Remove OH from both carboxylic acid functional group
Diols
An alcohol containing 2 -OH functional groups
Dicarboxylic acids
A carboxylic acid containing 2 -COOH groups
Diols examples
Methane diol (HO-CH2-OH)
Ethane diol (HO-CH2-CH2-OH)
Propane diol (HO-CH2-CH2-CH2-OH)
Dicarboxylic acids examples
Propane dioic acid (HOOC-CH2-COOH)
Butane dioic acid (HOOC-CH2-CH2-COOH)
Addition polymerisation vs Condensation polymerisation
Number of monomer types:
- Addition has one monomer type, alkene
- Condensation has 2 monomer types each containing 2 same functional group, or it has one monomer type which contains 2 different functional groups
Number of products:
- Addition has one, the addition polymerisation
- Condensation has 2, the condensation polymer and small molecule usually water
Functional group involved:
- Addition has the double carbon bond
- Condensation has which ever 2 functional groups are present on monomer e.g. COOH, OH, NH2
Proteins
Biological polymers made from amino acid monomers
How are different proteins produced?
There are around 20 different amino acids that can be joined in any combination to produce different proteins
In the body proteins can be…
- Enzymes
- Hormones
- Collagen
Amino acids - functional groups
Contain two functional groups: amine group, carboxyl group
Amino acids - formation of polymers
- Amino acids join together by condensation polymerisation to form polymers called polypeptides (proteins)
- The bond that joins two amino acids is called a peptide link
- When two amino acids join the product is called a dipeptide
Starch
- Glucose monomers join together to form starch polymers
- Starch is an example of a poly saccharide
- Living things use starch to store energy as a complex carbohydrate
Cellulose
- Glucose monomers join together to form cellulose polymers
- Cellulose is made by plants
- It is found in plant cell walls, and provides the plant cells (& plant) with structural support and protection
