Flashcards
Designer polymers
Flashcards do conjunto (13)
- 1Give five features of nylon.Nylon is tough, lightweight, keeps water out, keeps UV light out, does not let water vapour through.
- 2What happens to sweat when wearing nylon?This means that the sweat condenses and makes the wearer wet and cold inside their jacket.
- 3Give the properties of GORE-TEX.GORE-TEX has all the properties of nylon but is also breathable.
- 4What happens to sweat when wearing GORE-TEX?Water vapour from sweat can pass through the membrane but rainwater cannot.
- 5GORE-TEX material is waterproof yet breathable. What is it made from?It is made from PTFE (polytetrafluoroethene) / polyurethane membrane.
- 6What is specials about the holes in PTFE?The holes in PTFE are too small for water to pass through but are big enough for water vapour to pass through.
- 7PTFE/polyurethane membrane is too fragile on its own. How is it made stronger?It is too fragile on its own and so it is laminated onto nylon to produce a stronger fabric.
- 8Scientists are developing new types of polymers. What are the properties of these new types of polymers?Scientists are developing new types of polymers:
- polymers that dissolve
- biodegradable polymers - 9Why is research into new polymers important?Research into new polymers is important because there are environmental and economic issues with the use of existing polymers.
- 10What are the current environmental and economic issues with existing polymers?- Disposal of non-biodegradable polymers means landfill sites get filled quickly.
- Landfill means wasting land that could be valuable for other purposes.
- Disposal by burning waste plastics makes toxic gases.
- Disposal by burning or using landfill site wastes the crude oil used to make the polymers.
- It is difficult to sort out different polymers so recycling is difficult. - 11What are atoms in polymers held together by?Atoms in polymers are held together by strong covalent bonds.
- 12The properties of plastics can be related to simple models of their structure. Fill in the gaps: - Plastics that have .... intermolecular forces ....... polymer molecules have ... melting points and can be ......... easily as polymer ......... can slide over each other.- Plastics that have weak intermolecular forces between polymer molecules have low melting points and can be stretched easily as polymer molecules can slide over each other.
- 13The properties of plastics can be related to simple models of their structure. Fill in the gaps: - Plastics that have ...... forces ....... polymer molecules have .... melting points, cannot be ......... and are ......Plastics that have strong forces between polymer molecules have high melting points, cannot be stretched and are rigid.
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- GCSE Science Year 10 FlashCards sobre Designer polymers, criado por annjb2898 em 19-05-2014.
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