C2 2.5+ Polymers And Nanoscience Flashcards
What do polymer properties depend on?
The polymer properties depend on the monomers used to make it and the conditions where the reaction occurs.
What are polymers?
Polymers are groups of monomers joined together.
What are thermosoftening polymers?
Thermosoftening polymers are polymers which soften easily and they reset when they cool down. They are made up of individual polymer chains that are tangled together.
What are thermosetting polymers?
Thermosetting polymers are polymers which do not melt when we heat them. These have strong covalent bonds forming ‘cross links’ between their polymer chains.
Bonding in polymers
The atoms in polymer chains are together by very strong covalent bonds.
In thermosoftening polymers, the intermolecular forces between the polymer chains are weak this is why they melt easily. When the polymer cools down, the intermolecular forces bring the polymer molecules back together.
In thermosetting polymers, the covalent bonds are strong and they stop the polymer from softening. The covalent ‘cross links’ do not allow the polymer chains to separate. Although, the polymer will char at high temperatures.
What is nanoscience?
Nanoscience is the study of small particles that are between 1 and 100 nanometres in size.
Uses of nanoscience
Sun screens- scientists coat nanoparticles of the metal oxide with a coating of silica. The thickness of the silica coating can be adjusted at an atomic level. These coated nano particles block UV radiation well.
Glass can be coated with titanium oxide nano particles. Sunshine triggers a chemical reaction which breaks down dirt which lands on the window. When it rains, the water washes off the dirt.
Possible risks of nanoscience
The large surface area of the nanoparticles could make them dangerous if a spark is made by accident.
Also, breathing in the tiny nanoparticles could cause damage to the lungs.
