Polymers & waste Flashcards
1
Q
what is a polymer?
A
a chain of many monomers
2
Q
what is addition polymerisation?
A
unsaturated monomers open their double bond to form saturated chains
3
Q
state an example of a synthetic polymer
A
poly (ethene)
4
Q
describe characteristics of polymers
A
- saturated
- usually non polar so unreactive
- do not easily degrade
5
Q
what are the weaknesses of sending plastics to landfill?
A
- cannot separate
- takes up space
- expensive
- most polymers do not biodegrade
6
Q
what are advantages of recycling plastics?
A
- reduces dependency on crude oil
- can be remoulded
- can be cracked or used as organic stock feed
7
Q
what is an advantage and weakness of incinerating plastics?
A
- generates electricity
- produces toxic HCl gas when burning but this is overcome by neutralising with NaOH
8
Q
what is feedstock recycling and how is it used?
A
reclaiming monomer/gas/oil where products resemble crude oil products
can be used as raw material to create new polymers
9
Q
what is a weakness of feedstock recycling?
A
cannot deal with unsorted or unwashed polymers
10
Q
what are biodegradable polymers used for?
A
- breaks down into water, CO2 or biological compounds
- alters polymer structure to allow them to break down
11
Q
what are weaknesses of biodegradable polymers?
A
- made from oil fractions and renewable sources which are expensive
- oxygen and moisture are required
