polymers and waste Flashcards
what is a polymer?
a chain of many monomers
state 2 examples of natural polymers
proteins
rubber
state an example of a synthetic polymer
poly (ethene)
describe characteristics of polyalkenes
- saturated
- usually non polar so unreactive
- do not easily degrade
what are the weaknesses of sending plastics to landfill?
- cannot separate
- takes up space
- expensive
- most polymers do not biodegrade
what are advantages of recycling plastics?
- reduces dependency on crude oil
- can be remoulded
- can be cracked or used as organic stock feed
what is an advantage and weakness of incinerating plastics?
- generates electricity
- produces toxic HCl gas when burning but this is overcome by neutralising with NaOH
what are biodegradable polymers?
polymers which decompose naturally
why do biodegradable polymers not need to be disposed of?
they are decomposed by organisms
what are weaknesses of biodegradable polymers?
- made from oil fractions and renewable sources which are expensive
- oxygen and moisture are required
what is addition polymerisation?
unsaturated monomers open their double bond to form saturated chains
what is the concern with disposing of alkenes?
- not very reactive
- non biodegradable
what is the reason for recycling alkenes?
- conserves fossil fuels
- prevents landfill
what is feedstock recycling and how is it used?
- reclaiming monomer/gas/oil where products resemble crude oil products
- can be used as raw material to create new polymers
what is a weakness of feedstock recycling?
cannot deal with unsorted or unwashed polymers
