C11 - Polymers Flashcards
(35 cards)
What is a polymer
a substance made from very large molecules made up of many repeating units
What are monomers
small reactive molecules that react together in repeating sequences to form a large polymer
what is polymerisation
polymerisation is when many small monomers join together to form a large polymer
What happens when alkene molecules join together
The double covalent bond between the two carbon atoms ‘opens up’. It is replaced by a single c-c covalent bond and the monomer then had an empty covalent bond which allows the monomer to bond with multiple monomers. This type of reaction is called addition polymerisation and the polymer is called an addition polymer
What conditions does the addition polymerisation of alkenes need
A very high temperature (200C) and pressure to break the alkene bonds and a catalyst
What is special about the products of addition polymerisation
The only product is a polymer so an addition polymer contains exactly the same type and number of atoms as the monomers that formed it.
What do ethene, propene and chloroethene polymerise to form
- Ethene polymerises to form poly(ethene) or polythene
- Propene polymerises to form poly(propene) or polypropylene
- Chloroethene polymerises to form poly(chloroethene) or PVC
Why are alkenes good monomers
because they are unsaturated
Poly(ethene) uses and properties
- Useful plastic as it is strong and easy to shape
- Transparent except when colouring material is added to it
- Makes ‘plastic’ carrier bags, some drinks bottles, dustbins, washing up bowls and cling film
Poly(propene) uses and properties
- Very strong tough plastic
- Used to make carpets, milk crates and ropes
Poly(chloroethene) uses
Used in water pipes and a insulation on electricity cables
What are condensation polymers made from
Condensation polymers are made from monomers which contain different functional groups and are not alkenes.
What is special about the products of condensation polymerisation
For each new bond that forms, a small molecule (such as water or hydrogen chloride) is released so therefore there are two different products
What do the simplest types of condensation polymer contain
they contain two different types of monomer each with two of the same functional groups
How is an ester formed
An alcohol (-OH functional group) and a carboxylic acid (-COOH) react together to give an water plus water.
what is a diol
an alcohol containing two -OH groups
what is a dicarboxylic acid
a carboxylic acid containing two -COOH groups
How are polyesters formed
Polyesters are formed from the condensation polymerisation of a diol and a dicarboxylic acid, with water given off in the reaction
Addition Polymerisation:
- Number of monomer types
- Number of products
- Functional groups involved in polymerisation
- Only one monomer type containing a C=C bond
- Only one product formed
- Carbon-Carbon double bond in monomer
Condensation Polymerisation
- Number of monomer types
- Number of products
- Functional groups involved in polymerisation
- Two monomer types contains two of the same function group OR one monomer type with two different functional groups
- Two types of product, the polymer and a small molecule
- Two reactive groups on each monomer
Making Nylon
1.Put a thin layer of monomer A into the bottom of a small beaker
2.Pour a layer of monomer B on top of this
3. Gently draw a thread out of the beaker using a pair of tweezers and wind it around a test tube
SAFETY: Wear gloves and eye protection, do not touch nylon formed and carry out in fume cupboard or well ventilated lab
What are carbohydrates and what is their general formula
Carbohydrates are compounds made up of molecules containing carbon, hydrogen and oxygen atoms.
They have the general formula Cx(H2O)y and are made up of one or more types of sugar molecules
What are glucose and fructose and what is their structure
They are both monosaccharides (made up of one sugar unit)
Glucose has a six membered ring structure and Fructose has a five membered ring structure
What do monosaccharides bond together to make
they bond together to make larger polymer molecules called Polysaccharides