AQA unit 4 polymers

Polymers
AQA Chemistry Unit 4
Frihah Parvaiz

Addition polymers
be able to draw the repeating unit of addition polymers from monomer structures and vice versa




Condensation polymers
understand that condensation polymers may be formed by reactions between dicarboxylic
acids and diols, between dicarboxylic acids and diamines and between amino acids




Ethandioic acid
1,4 dicarboxylic acid




1

Dicarboxylic acids and diols react together
to produce polyesters with the repeating
unit, COO. A molecule of water is also
released. Terylene is a polyester made
from the combination of ethane, 1,2 diol
and benzene, 1,4 dicarboxylic acid.
Ethane 1,2 diol




Making a polyester. A and B represent unspecified organic…

know the linkage of the repeating units of polyesters (e.g. Terylene) and polyamides (e.g. nylon 6,6 and Kevlar)




Polyamides have the amide
linkage, CONH repeated. To
make polyamides a
diaminoalkane and a
dicarboxylic acid have to react.
The general equation for making a polyamide Hexane 1,6dioic acid reacts
with hexane,…

understand that polyalkenes are chemically inert and therefore non-biodegradable


Although they are called polyalkenes they are actually
saturated molecules and therefore have no bond polarity and
are chemically inert. They are very difficult to react unless
there is UV light present to split the molecules.They are not
biodegradable and pose…

Bonding in polymers
The biggest difference between
a) The density and strength of addition polymers varies. They depend to a addition and condensation
extent on the length of the hydrocarbon chain, but depend much more polymers is that addition
strongly on the nature and extent of the branching on the…

appreciate the advantages and disadvantages of different methods of disposal of polymers




Method Advantage Disadvantage
Buried Cheap and Easy Requires large areas of land
Stops build up of landfill sites Methane released as the waste decomposes
Leaks can contaminate water supplies
Burned The heat can be used to generate Process…

SUMMARY OF POLYMER FORMATION AND HYDROLYSIS REACTIONS

Type of reaction Mechanism

1. Addition polymerisation (alkenes polyalkenes) Free radical
conditions: high temperature, Ziegle-Natte catalyst
addition
equation: (not required)


n C C C C


n


2. Condensation polymerisation
Nucleophilic
a) polyesters
dicarboxylic acid + diol polyester
addition-
conditions: H2SO4, heat under reflux…

equation:
O
O
O O
HO C R1 C
+ 2n NaOH n C R1 C + n HO R2 OH +H O 2
n/a
O R2 O H

Na+ O- O- Na+
n



b) polyamides
reagents: HCl(aq)
conditions: heat
equation:
H H
O O
O O
R1 C
+…

a) Recall that alkenes can form addition polymers and draw
structures for polymers given the monomer and vice versa


b) Recall that diacid chlorides or diacids can react with diols or
diamines to form condensation polymers, draw the repeating units of
polyesters and polyamides and know the structures of terylene…