PL - Polymers Flashcards
What are the two ways of making polymers?
Addition polymerisation and condensation polymerisation.
What are addition polymers formed from?
Alkenes.
How do alkenes form addition polymers?
The double bonds in alkenes can open up and join together to make long chains called addition polymers.
What are the monomers for addition polymers?
Alkenes.
What do condensation polymers include?
Polyesters and polyamides.
What does condensation polymerisation usually involve?
Two different types of monomer each of which has at least two functional groups.
How are condensation polymers formed?
Condensation polymerisation usually involves two different type of monomer, each of which has at least two functional groups. Each functional group reacts with a group on another monomer to form a link, creating polymer chains.
In condensation polymerisation, what is lost every time a link is formed?
A small molecule (usually water).
What is an example of a natural condensation polymer?
Proteins.
What are the two types of condensation polymer that you need to know about?
Polyesters and polyamides.
What are polyamides made from?
Dicarboxylic acid and diamine monomers.
What reacts between a dicarboxylic acid and a diamine to form a polyamide/amide links?
Carboxyl groups react with amino groups to form amide links.
What causes an amide link to form?
Carboxyl groups react with amino groups to form amide links.
What links are formed in the condensation polymerisation which makes a polyamide?
Amide links.
What size are the chains that polyamides form?
long or short?
They form long chains as dicarboxylic acids and diamines have functional groups at each end of the molecule, so long chains form.
What can the amide links in polyamides be broken down by?
Hydrolysis.
What does the hydrolysis of polyamides reform?
The dicarboxylic acid and diamine monomers.
What are polyesters made from?
Dicarboxylic acid and diol monomers.
What reacts between a dicarboxylic acid and a diol to form a polyester/ester links?
Carboxyl groups (-COOH) react with hydroxyl (-OH) to form ester links (-COO-).
What polymer is formed from a dicarboxylic acid and a diamine?
A polyamide.
What polymer is formed from a dicarboxylic acid and a diol?
A polyester.
What links are formed in the condensation polymerisation which makes a polyester?
Ester links.
What causes an ester link to form?
Carboxyl groups (-COOH) react with hydroxyl (-OH) to form ester links (-COO-).
What can the ester links in polyesters be broken down by?
Hydrolysis.
What does the hydrolysis of polyesters reform?
The dicarboxylic acid and diol monomers.
How do you show something is a polymer repeating unit?
Draw brackets around where it repeats/the repeating unit and put an ‘n’ after it.
What do you join together to find a condensation polymer?
The monomer functional groups.
How do you work out the (formula of the) condensation polymer that would form from 2 monomers?
- Draw out the two monomer molecules next to each other.
- Remove an OH from the dicarboxylic acid, and an H from the diamine/diol to give a water molecule.
- Join the C and the N/O together to make an amide/ester link.
- Take another H and OH off the ends of your molecule.
- Draw brackets around the molecule, add an ‘n’ outside the brackets and there’s the formula of your polymer.
What does the ‘n’ after the brackets show?
That you’ve got lots of the monomers, and the polymer contains lots of the section shown in the brackets.
What is the ‘repeat unit’ of a polymer?
The same as the structural formula, but you don’t need the brackets or the ‘n’.
What do you break to find the monomers of a condensation reaction?
The amide or ester link.
How can you find the formulas of the monomers used to make a condensation polymer?
By looking at its formula.
1) First find the amide (HN-CO) or ester (CO-O) link. Break it down the middle.
2) The add a H or an OH to both ends of both molecules to find the monomers.
(Always add Hs to O or N atoms, and OH groups of C atoms.)
How do you know where to add the Hs and Oh groups when breaking up a condensation polymer into its monomers?
Always add Hs to O or N atoms, and OH groups of C atoms.
What can molecules that contain both an amine and an alcohol group do?
React with dicarboxylic acids in a condensation polymerisation reaction so that the polymers contain both amide and ester links.
How are polymers that contain both amide and ester links shown?
One of the links is in the ‘middle’ of the molecule and the other link is split across the ends of the polymer formula.
Why can it be hard to see that a polymer contains both ester and amide links?
Because ne of the links is in the ‘middle’ of the molecule and the other link is split across the ends of the polymer formula.
What can a single molecules that contain both a carboxylic acid group and either an alcohol or an amine group do?
It can polymerise itself to form a condensation polymer with only one monomer.
What are the differences in terms of the type of monomer in addition polymers and condensation polymers?
Addition polymers - alkenes.
Condensation polymers - each monomer must have at least two functional groups able to react. E.g. diols and dicarboxylic acids (to form polyesters), or diamines and dicarboxylic acids (to form polyamides).
What are the differences in terms of the polymerisation reaction in addition polymers and condensation polymers?
Addition polymers - addition reaction, where the C=C bonds in the alkene monomers open up and join together to form long chains.
Condensation polymers - condensation reactions, where the functional groups on alternate monomers react together to form an amide or ester link, resulting in water being released.
What are the differences in terms of polymer reactivity in addition polymers and condensation polymers?
Addition polymers - the main polymer chain is unreactive.
Condensation polymers - the links between monomers are amide or ester links, which can be hydrolysed under acidic or basic conditions, to break down the polymer and reform the original monomers.
What are the 3 differences between addition polymers and condensation polymers?
Type of monomer:
1) Addition polymers - alkenes.
2) Condensation polymers - each monomer must have at least two functional groups able to react. E.g. diols and dicarboxylic acids (to form polyesters), or diamines and dicarboxylic acids (to form polyamides).
Polymerisation reaction:
1) Addition polymers - addition reaction, where the C=C bonds in the alkene monomers open up and join together to form long chains.
2) Condensation polymers - condensation reactions, where the functional groups on alternate monomers react together to form an amide or ester link, resulting in water being released.
Polymer reactivity:
1) Addition polymers - the main polymer chain is unreactive.
2) Condensation polymers - the links between monomers are amide or ester links, which can be hydrolysed under acidic or basic conditions, to break down the polymer and reform the original monomers.
Give an example of a polyamide:
Nylons.
