Organic Chemistry - SPEC Flashcards
how are polymers made and what is this process called
made by linking together large numbers of monomers
addition polymerisation
how is each monomer connected within a polymer
with covalent bonds
what conditions do polymerisation reactions need
- high pressures
- the use of a catalyst
what are synthetic polymers
those that are manufactured such as polystyrene and nylon
how to change a polymer into a polymer (for a drawing)
remove the two extending single bonds and create a double bond instead
why are polymers a problem for the environment
they have strong C-C bonds which makes them unreactive and chemically inert so they don’t easily biodegrade
what are the options for disposing of polymers
- landfill
- incineration
- recycling
why is landfill not a good option for disposing of polymers
this takes up valuable land because site quickly fill up
why is incineration not a good option for disposing of unwanted polymers
- they release the greenhouse gas carbon dioxide
- polymers that contain chlorine release hydrogen chloride gas when burned
- if incinerated with incomplete combustion then carbon monoxide is produced
what are the problems with recycling unwanted polymers
different polymers must be separated from each other which is a difficult and expensive process
when are condensation polymers formed
when two different monomers are linked together with the removal of a small molecule - usually water
what is a key difference between addition polymerisation and condensation polymerisation
addition polymerisation forms the polymer molecule only
WHEREAS
condensation polymerisation forms the polymer molecule (polyester) and one water molecule per link
WHAT ARE THE REACTANTS AND PRODUCTS OF CONDENSATION POLYMERISATION
REACTANTS = dicarboxylic acid, diol
products = polyester, water
what is a dicarboxylic acid monomer
a carboxylic acid with a -COOH group at BOTH ends
what is a diol
an alcohol with an -OH group on BOTH ends
how do the diols and dicarboxylic acids react with each other to form a polymer
Each -COOH group reacts with another -OH group on another monomer
this creates a long chain of alternating monomers
how is water formed in condensation polymerisation
For every ester linkage formed, one molecule of water is formed from the combination of a -H and an -OH group
give one example of a dicarboxylic acid
ethanedioic acid
-dioic
give one example of a diol
ethanediol
- diol
what do each of the atoms come from that form water in condensation polymerisation
The OH comes from the -COOH groups of the dicarboxylic acid
The H comes from the -OH groups of the diol
what is hydrolysis
adding water to the polyester which allows it to break back down into its monomers, reversing condensation polymerisation
how to deduce the monomers from the polyester
- then the OH atoms are added back onto the C=O
and H atoms added onto the oxygen atoms on the other structure