Polymers Flashcards
What are the monomers of addition polymers?
alkenes
What are the 2 lines extending out of the square brackets called?
trailing bonds
What are the properties of poly(alkenes)?
saturated
non-polar
unreactive
do not degrade well in landfill
What are the 2 types of condensation polymers?
polyamides and polyesters
What is condensation polymerisation?
2 different monomers with at least 2 functional groups react together
when they react a link is made and water is eliminated
What monomers are polyamides produced from?
diamides and dicarboxylic acids
What are the monomers for producing polyesters?
a diol and a dicarboxylic acid
What links form in a polyamide?
amide links
Why do monomers in condensation polymerisation need 2 functional groups?
so they have functional grous either side of the molecule which allows chains of monomers to be formed by links
What link is formed in the production of polyesters?
ester links
What is produced when you hydrolyse a condensation polymer?
the original monomers
How many water molecules are produced per 1 condensation polymer produced?
2n
What can happen if a monomer has a carboxylic group and a amine group?
it can react with itself to form an amide link = polymamide formed
What is the structure of a ester linkage?
O=C-O-
(another bond from C)
Why is it more efficient to use an acyl chloride condensation than using carboxylic acids in condensation polymerimerisation to produce polyesters and polyamides?
a higher yield and does not require a conc acid catalyst
What is the by product of condensation polymerisations using acyl chlorides?
HCl
What is the structure of a amide linkage?
O=C-NH-
What are the 2 ways a polyester can be formed?
carboxylic acid and alcohol
alcohol and acyl chloride
what is the most important polyamide?
proteins
What monomers are proteins made from?
alpha amino acid molecules
What are the 2 ways polyamides can be formed?
a monomer with both an amine and carboxylic acid group
using 2 monomers = diamine and dicarboxylic acid
What does it mean that polyesters and polyamides are chemically degradable?
they can undergo hydrolysis when heated under reflux with aq HOT acid/ alkali to be broken down into their respective monomers
What is added and produced to acid catalysed hydrolysis of a polyester?
added = h2o
produced = 2 monomers
What is added and produced to base catalysed hydrolysis of a polyester?
added = OH-
produced = salt and diol
What is added and produced to acid catalysed hydrolysis of a polyamide?
added = H2O and H+ (HCl)
produced = dicarboxylic acid and +NH3-R-NH3+ (amine salt)
What is added and produced to base catalysed hydrolysis of a polyamide?
added = OH-
produced = carboxylic acid salt + diamine
What is an advantage of using addition and condensation polymers?
they are produced easily and cheaply from alkenes and petroleum
what is an issue of addition and condensation polymers?
they are non-biodegradable = will remain in landfill for an extremely long time and can harm animals if accumulating in oceans
How can sustainability of throwing away plastics be improved?
recycle
burn them and the heat released can be used to generate electricity
chemical feedstock = converted chemically into other useful products eg: alkenes
What is the issue with burning chlorinated polymers?
HCL is produced and needs to be removed
How can HCL be removed when burning chlorinated polymers?
neutralisation with aq alkali = NaOH
What are biodegradable polymers?
can be broken down by microorganisms (enzyme-catalysed hydrolysis)
What are photodegradable polymers?
broken down by UV light
What is hydrolysis?
the chemical breakdown of a substance by adding water
what is the use of polyamides?
fibres in clothing
What 2 functional groups does an amino acid have?
carboxyl and NH2
