Polymers Flashcards
What is a condensation reaction?
Two different monomers are joined together with a condensation reaction.
How are polyamides formed?
Reactions between dicarboxylic acid and diamines.
What is the bond in a polyamide?
an amide link
Draw the repeating unit for the formation of Nylon-6,6 from the reaction of hexanedioic acid and 1,6-diaminehexane.
What are the properties of Nylon-6,6 and what are they used for?
It is strong and resistant to abrasion so it is used to make clothes: carpets and ropes.
Draw the repeating unit for the formation of kevlar from the reaction of Benzene-1,4-dicarboxylic acid and 1,4-diaminobenzene
What are the properties of kevlar and what are they used for?
It is light and very strong so it is used for bulletproof vests and car tyres.
What is an example of a polyamine?
a polypeptide chain.
How are polyesters formed?
The formation of an ester link between a dicarboxylic acid and a diol and the removal of water.
Draw the repeating unit for the formation of Terylene from the reaction of Benzene-1,4-dicarboxylic acid and Ethane-1,2-diol.
What are the properties of Terylene and what are they used for?
It is stable in both cold and hot temperatures so it is used for containers and plastic bottles.
Why do polyamines and polymers have higher melting and boiling points compared to polyalkenes?
In polyamines, hydrogen bonds can form between the C-O groups and N-H group. In polyesters permanent dipole-dipole forces can form. These forces are stronger and need a lot more energy to break compared to the van der Waals forces in the polyesters.
Why are polyalkenes very unreactive?
The bonds are non-polar meaning they can’t be attacked by nucleophiles.
What is the disadvantage of polyalkenes being inert?
They are non-biodegradable.
Why are polyamines biodegradable?
the bonds are polar meaning they can be attacked by nucleophiles like water and broken down
What are the advantages of using landfills for waste disposal?
It is a relatively cheap and easy method of water disposal.
What are the disadvantages of using landfills for waste disposal?
- It takes up land
- As the waste decomposes it releases methane which is a greenhouse gas.
- Any toxic chemicals released when the waste decomposes can contaminate water supplies.
What are the advantages of using incineration for waste disposal?
The heat produced can be used to generate electricity.
What are the disadvantages of using incineration for waste disposal?
- When some polymers are burned they release toxic gases like PVC releasing HCl when burned.
- Releases carbon dioxide which is a greenhouse gas that contributes to the greenhouse effect.
What are the advantages of using recycling for waste disposal?
- Less garbage ends up in landfills.
- Produces less carbon dioxide compared to burning plastic.
- It saves on raw materials like oil which is used to make the alkanes.
What are the disadvantages of using recycling for waste disposal?
Collecting, sorting and processing the plastics takes time and is expensive.
