unit 6 section 3 polymers Flashcards
explain condensation polymerisation
this involves two different types of monomer, each monomer has functional groups. the functional group of each monomer to form a link, creating a polymer chain.
what are some examples of condensation polymers
polyamides, polyesters and polypeptides
how are polyamides formed
they are formed by a reaction between dicarboxylic acids and diamines make polyamides.
this is done by the carboxyl groups from the dicarboxylic reacts with the amino groups of diamines to form amide links.
what do amino acids contain
they contain an amine functional group and a carboxylic acid functional group.
what happens in the hydrolysis of polyesters and polyamides
the ester or amide link in polyester and polyamides are broken by hydrolysis. the water molecules are added back and the links broken. the product of the reaction is a monomers that are used to make polymers and water.
which polymers are stronger condensation polymers and addition polymers
condensation polymers are stronger and more rigid than addition polymers. this is because condensation polymers are made up of polar bonds, as well as induced dipole-dipole forces, there are permanent dipole - dipole forces and very strong hydrogen bonds between the polymer chains.
how do you find out the repeating unit of a polyamide
- first draw out the two monomer molecules next to each other
- remove an OH from the dicarboxylic acid, and a H from one of the diamine - that gives you the water molecule
- join the C=O and the N together to make the amide link
- take a H of the other nitrogen atom, and an OH of the COOH group at the ends of your molecule.
are polyalkanes chemically inert
yes , e.g. polyethene , polystrene
why are polyalkanes chemically inert
this is because the repeating units are non-polar, so they are not susceptible to attacks by neuclophiles.
give an example of using a chemically inert polymer
the polymer wont react with other things for example the polystyrene wont react with the coffee it is holding
give a disadvantage of using a chemically inert polymer
the polymer is non - biodegradeable . the polymer cannot be hydrolysised and cannot break down naturally.
explain why condensation molecules are biodegradeable
they are susceptible because the bonds can be broken by hydrolysis, this is because the bonds between repeating units are polar and are susceptible to attacks by nucleophiles such as water.
however the process is very slow
what are the 4 ways of disposing of waste plastics
burying,burning recycling and reusing.
what are the disadvantages of burying waste
- it requires areas of land
- as the waste decomposes it can release methane
- as the waste decomposes it can release toxins that can be washed away and contaminate water supplies
give the disadvantages and advantages of burning polymers
adv - they can be burned to produce energy
dis- produces toxic gases - this has to be removed by passing them through a scrubber which neutralises by allowing them to react with a base.