Polymers Flashcards
Properties of Polypropythene (PP)
Flexible,tough,lightweight,food safe
What are thermoplastics made from?
Long chain polymers joined by weak chemical bonds
What happens to thermoplastics when heated?
The bonds break, making the plastic ‘semi fluid’ and able to be shaped
Can thermoplastics be recycled?
Yes, they can be recycled by melting them down and reforming their shape
What characterizes thermosetting plastics?
They undergo a chemical change when set and cannot be softened by further heating
What are the main manufacturing methods for thermosets?
Casting, moulding, and laminating
What was the first synthetic plastic?
Celluloid
What raw materials are commonly used in the production of plastics?
Coal or oil
What is fractional distillation used for in plastic production?
To separate different chemicals into parts
What are monomers?
Small molecules that are chemically joined to make longer molecular chains called polymers
What do plasticisers do?
Make plastic bendy
What are elastomers?
A type of thermoset with ‘springy’ bonds giving a rubbery quality
What is ebonite?
An early form of plastic used to simulate ebony, hard and used for bowling balls
What are composites?
Materials combined to achieve specific advantages
Give examples of composites.
- Kevlar
- GRP (Glass reinforced plastic)
- Graphite
- Carbon Fibre
What is Acrylonitrile Butadiene Styrene (ABS) known for?
Being strong, tough, scratch resistant, and resistant to heat and chemicals
What is High Density Polythene (HDPE) used for?
Bottles for bleach and shampoo, toys, buckets, and piping
What is the main use of Polystyrene (PS)?
Making vending cups and model kits
What is Low Density Polythene (LDPE) commonly used for?
Thin film, carrier bags, wiring insulation, and squeezy bottles
True or False: Thermosetting plastics are recyclable.
False
What are the environmental problems associated with plastics?
- Long shelf life makes disposal difficult
- Do not rot or corrode
- Produce black choking gases when burnt
- Can cause severe burns when molten
- Plastic production can be polluting
What is Phenol Formaldehyde known for?
Being tough and heat resistant, often black in color
What are epoxy resins used for?
Making adhesives and flooring
Fill in the blank: The chemical process that converts raw materials into plastics involves joining small molecules called _______.
Monomers
