Flashcards
Polymers and New Materials
Flashcards do conjunto (7)
- 1Smart Materials (2)1. They behave differently depending on conditions (temperature).
2. This has a number of uses such as glasses frames and dental braces. - 2Nanoparticles1. Consist of a few hundred atoms.
2. Have very different properties to the bulk chemical they're made from. - 3Nanomaterial Uses1. Industrial catalysts (huge surface area to volume ratio).
2. Highly specific sensors.
3. Used to make stronger, lighter buildings materials.
4. New cosmetics.
5. Tiny electric circuits for computer chips. - 4Thermosoftening Polymers1. Don't have cross-linking between chains.
2. Easy to melt the weak forces.
3. When it cools, the polymer hardens into a new shape.
4. You can repeatedly melt these polymers. - 5Thermosetting Polymers1. They have cross links.
2. These hold the chains together in a solid structure.
3. The polymer doesn't soften when it is heated.
4. Thermosetting polymers are strong, hard and rigid. - 6Low Density (LD) PolytheneMade by heating ethene to about 200C under high pressure. It is flexible and is used for bags and bottles.
- 7High Density (HD) PolytheneMade at a lower temperature and pressure (with a catalyst). It's more rigid and is used for water tanks and drain pipes.