The Materials Revolution Flashcards
What makes a bond polar?
Two atoms of different electronegativites, the bonding electrons are pulled towards the more electronegative atom.
What is permanent dipole- permanent dimple bonding?
The delta + and the delta - charges on a polar molecules cause a weak electrostatic forces of attraction between molecules.
What’s the difference between an amide and an amine?
Amides have the functional group -CONH2. Amines just have a -NH2 group.
What do you make when you hydrolyse an amide with dilute acid?
Carboxylic acid and ammonium salt
What do you make when you hydrolyse an ester by refluxing an ester with a dilute acid?
Carboxylic acid salt and an alcohol
What do you make when you hydrolyse an amide with dilute alkali?
An carboxylate ion and ammonia has given off
Reaction between dicarboxylic acids and diamines make what? What reaction is this?
Polyamides and water - condensation polymerisation
Reaction between dicarboxylic acids and diols make what? What reaction is this?
Polyesters and water - condensation polymerisation
What are the properties of thermoplastic? And why?
Soft and flexible. Polymer chains can slide over one another easily.
What is the Tm? What happens if it is reached?
It’s the melting point of thermoplastic polymers. If it reached above the Tm it will soften and then melt
What is the Tg? What happens if it is reached?
Glass transition temperature, cooling the thermoplastic below the temperature causes the polymer to become brittle and shatter
What are the arrangement of chains in a crystalline polymer?
They are ordered and run in the same direction
What are the arrangement of chains in a amorphous polymer?
The arrangement of chains are random, they run in all directions
What is copolymerisation?
Making a polymer by using a mixture of monomer molecules
How does a plasticiser make a polymer bendier?
The plasticiser molecules get between the polymer chains and push them apart. This reduces the strength of the intermolecular forces between the chains- so they can slide around more.
