Polymers Flashcards
Polymer
A substance of high relative formula mass made up of small repeating units called monomers
How can alkenes act as monomers to form polymers?
By opening up their double bond
And joining together in a long chain
Addition polymerisation
Process of opening up the double bond to ‘add’ monomers together to form a large molecule
Monomer represented as
The displayed formula of the Alkene with small n
Polymer represented as
No double bond
Bracket around monomer
Bonds extend out of the bracket
n on the outside
Repeating unit
A short hand way of representing a polymer using a bracket and n
How to name polymers
Poly(Alkene)
Waste polymers
After a product has been manufactured, requires sorting into 3 ways
3 ways waste polymers dealt with
Recycling
Incineration to release energy
Use as feedstock for cracking into new plastics or other chemicals
Recycling polymers
By sorting polymers first, then converting to other materials to be reused
By melting + remoulding
Incineration to release energy
Burning polymer waste for fuel by breaking bonds which releases energy
Problems with incineration to release energy
Some polymers contain toxic chemicals such as chlorine which release toxic hydrogen chloride (HCl gas)
How can chemists can prevent problem of incinerators releasing toxic gas?
Pass through scrubbers which will neutralise toxic gases
Separate plastics to avoid burning of chlorine containing ones
Chemical feedstock
By cracking a polymer back down into monomers it can be used to make new products: new plastics or other chemicals
Life cycle analysis
Illustrating the processes of making a polymer product including manufacture etc so chemists can contribute to more sustainable production
How to solve problem of polymers?
Unsustainable because made of non renewable fossil fuel hydrocarbons
So make biodegradable polymers
Biodegradable polymers
Can be decomposed by microbes so no problems with dealing with waste
What are biodegradable polymers made of?
Renewable materials eg Maize
Oil fractions
Advantages of using biodegradable polymers
Raw materials won’t run out like oil
Growing plants eg maize takes in co2 as it’s biodegraded so carbon neutral
Saves energy compared to oil based polymers
Disadvantages of biodegradable polymers
Collect + separate the biodegradable polymers from non biodegradable polymers so in right condition to decompose
More expensive
Sustainable polymer manufacturing process in terms of reactant molecules
Use safe + environmentally friendly reactant molecules
Use as few solvent molecules
Use renewable raw materials when possible
Sustainable polymer manufacturing process in terms of energy use
Energy use kept at a minimum
Use catalysts to lower energy use
Sustainable polymer manufacturing process in terms of product made
Limit waste products made which are hazardous to human health and environment
Make sure lifespan is appropriate for its use
