C1e-designer Polymers Flashcards
What properties do plastic bags and squeezy bottles need?
Light
Stretchable
What properties do window frames and piping have?
Strong
Durable
What is polystyrene foam used in?
Packaging to protect breakable things
Disposable coffee cups (thermal insulator)
What are the atoms in plastics held together by?
Strong covalent bonds
What kind of melting points do plastics with weak intermolecular forces between polymer molecules have?
Low melting points
Why can some plastics be stretched easily?
Weak intermolecular forces between polymer molecules
Polymer molecules can slide over one another
What kind of melting points do plastics with strong forces between polymer molecules have?
High melting points
Why are some plastics rigid and cannot be stretched?
Strong bonds (covalent bonds/cross linking bridges) between chains Crosslinks hold chains firmly together
What are the properties of nylon?
Tough Lightweight Keeps water out Keeps UV light out Doesn't let water vapour through Sweat condenses
What are the properties of GORE-TEX?
Tough Lightweight Keeps water out Keeps UV light out Breathable
How does GORE-TEX help active outdoor people?
If they sweat water vapour can escape
No condensation
Breathable
How is GORE-TEX waterproof and breathable?
Nylon laminated with PTFE
Holes in membrane too small for water to pass through
But big enough for water vapour to pass through
Membrane fragile on its own so combined with nylon
What is non biodegradable?
Will not decay or decompose by bacterial action
How can waste polymers be disposed of?
Use of landfill sites
Burning
Recycling
Why are chemists developing polymers that are biodegradable and dissolve?
So plastic thrown away breaks down/dissolves instead of sitting in landfill for a long time or being burnt
