Karteikarten
Designer Polymers.
Karten in diesem Stapel (17)
- 1What are polymers?They are plastics, which have many properties which make them useful.
- 2What are the properties of polymers?Can be easily moulded into shape.
Waterproof
Electrical insulator
Non-biodegradable
Lightweight
Flexible
Can be printed on
Unreactive
Can bicoloured
Heat insulator
Transparent
Tough - 3What properties and uses does polythene or poly(ethene) have?Properties:
Lightweight
Flexible
Easily moulded
Uses:
Plastic bags
Moulded containers - 4What properties and uses does polystyrene (expanded polystyrene) have?Properties:
Lightweight
Poor conductor of heat
Uses:
Insulation
Damage protection in packaging - 5What properties and uses does Nylon have?Properties:
Lightweight
Waterproof
Tough
Uses:
Clothing
Climbing ropes - 6What properties and uses does polyester have?Properties:
Lightweight
Waterproof
Tough
Uses:
Clothing
Bottles - 7Why is nylon an excellent material to use for making outdoor clothing?Because it is:
Lightweight
Tough
Waterproof (but it does not let water vapour escape, so it could be uncomfortable to wear if the wearer becomes hot and starts to perspire (not breathable))
Able to block UV light (harmful sunlight) - 8What is Gore-Tex?It is a breathable material made from nylon. It has all of the advantages of Nylon, but it is also treated with a, material that allows perspiration (water vapour) to escape whilst preventing rain from getting in. This is far more comfortable for people who lead an active outdoor life, as it prevents them from getting wet when they perspire.
- 9How is Gore-Tex made up?It has a membrane of polyurethane or
poly(tetrafluoroethane) (PTFE), sandwiched between two layers of nylon fibres. The laminated PTFE has very tiny holes that allows water vapour to pass through but that are too small to allow liquid water to pass through. The PTEF laminate is too weak and frgile to be used on its own. - 10What do polymer structures consist of?Polymers, such as poly(chloroethene) (PVC), consist of a tangled mass of very long-chain molecules, in which the atoms are held together by strong covalent bonds. The properties of a plastic depend on its structure.
- 11What happens to plastics that have weak forces between polymer molecules?They have low melting points and can be stretched easily as the polymer molecules can slide over one another.
- 12What happens to plastics that have strong forces between the polymer molecules.These strong forces between the polymer molecules are covalent bonds or cross-linking bridges. They have high melting points, are rigid and cannot be stretched.
- 13There are various ways of disposing of plastics, do they all have a negative impact on the environment?No not all of them, but some do. The main ways to dispose of them is in a landfill site, burning them or recycling them.
- 14Explain landfill sites and whether they have a negative impact on the environment or not when disposing of plastics?Using landfill sites is a problem because most plastics are non-biodegradable. This means microorganisms have no effect on them and they will not decompose and rot away. Throwing plastics into landfill sites results in the waste of a valuable resource and, because of the volume of waste produced, landfill sites get filled up very quickly, which is also a waste of land.
- 15Explain burning plastics and whether they have a negative impact on the environment or not when disposing of plastics?Burning plastics produces air pollution and also wastes valuable resources. The production of carbon dioxide contributes to the greenhouse effect which results in global warming. Some plastics cannot be burned at all because they produce toxic flames. For example, burning poly(chloroethene) or PVC as it is commonly known, produces hydrogen chloride gas.
- 16Explain recycling plastics and whether they have a negative impact on the environment or not when disposing of plastics?Recycling plastics is an option which prevents resources being wasted. However, different types of plastic need to be recycled separately. Sorting them into groups to be recycled can be difficult and very time-consuming.
- 17What are soluble plastics? Give an example.They are biodegradable plastics, which make disposal easy. For example, the plastic case of a dishwasher tablet is disposed of when it dissolves in contact with hot water, releasing detergent into the machine.
Informationen
- Beschreibung
- GCSE chemistry (C1) Karteikarten am Designer Polymers., erstellt von Rebecca Smith am 02/11/2016.
- Erstellt von
- Rebecca Smith
- Aufrufe
- 0
- Bewertung