11.
Comparing thermoplastics, thermosets & fibres - examples of synthetic
condensation polymers and natural polymers including proteins, DNA, wood, silk,
starch, cellulose
Including a comparison of thermoplastic addition
polymers with thermoplastic synthetic fibres from
condensation polymers and hard rigid thermoset plastics
Doc Brown's
chemistry revision notes: GCSE chemistry, IGCSE chemistry, O level
& ~US grades 8, 9 and 10 school science courses or equivalent for ~14-16 year old
students of chemistry
Sub-index for this
page
11A
Comparing
themoplastics, thermosets and fibres
11B
Synthetic condensation polymers like Nylon and Terylene
- basic structure, properties and uses
11C.
Examples of natural polymers,
their structure, function and uses e.g. starch, proteins, DNA
11D.
An
exercise in choosing a plastic for a
particular use
See also
Extra advanced Level notes on Nylon structure and synthesis
and
extra
Advanced Level notes of poly(alkene)
addition polymers
GCSE/IGCSE/O Level Oil Products & Organic Chemistry INDEX PAGE
See section 7. for full details on
addition polymers
ALL my Advanced
A Level Organic Chemistry revision notes

11A.
More on POLYMERS
- synthetic macromolecules
Polymers are long chain molecule formed from
lots of repeating units joined together by strong covalent bonds.
Modifying polymers, thermoplastics and
thermosets
- First some
reminders from section 7. about addition polymers which were discussed
in some detail.
-
As an example the formation of PVC is shown below.
-
the long chain PVC molecules
-
and
what the molecules look like in the structure of PVC or any other
thermoplastic.
-
Although the PVC molecules
look straight, in reality, the long molecules will be all
twisted-jumbled up as in the thermoplastic diagram above (a bit
spaghetti like!).
-
This
is a typical addition polymer (formed by simple addition of monomer
molecules), just like polythene and polystyrene etc. AND they are examples
of thermoplastics, that is they can be heated and softened, reshaped and
cooled to keep their new moulded shape.
-
In addition polymerisation there is
only one monomer molecule with a double bond and one product, the polymer,
and the linking occurs via a reactive double bond.
Detailed addition polymer notes
-
In
condensation polymerisation
there are monomer molecules with a reactive functional
groups.
-
There are two products, the condensation polymer itself, and, the
small molecule that is eliminated between the two monomer molecules
when the linking bond is formed from the two functional groups.
-
Thermoplastic polymers (thermoplastics)
-
A molecular model for a
thermoplastic
-
In thermoplastics the
intermolecular forces between the polymer molecules are quite weak
compared to the strong covalent bonds (C-C) holding the chain of atoms
together.
-
Because the 'intermolecular
bonding' is weak, this explains that when heated, these 'plastic'
materials will soften quite easily, which is why they are called
'thermoplastic' and have relatively low softening points and melting
points.
-
Even at room temperature the
plastic is easily distorted because the polymer chains can slide over
each other i.e. the external physical force applied on bending overcomes
the intermolecular forces between the polymer molecules.
-
Despite their relative
weakness, on controlled heating until they are quite soft (but NOT
molten), they are readily extrusion moulded or drawn out into useful
shapes which retain their new formation on cooling.
-
So, overall, thermoplastics
are not that heat resistant or exceptionally rigid/strong - but their
properties do vary quite widely e.g. poly(propene) and nylon can be
drawn into strong fibres and both can be manufactured into quite strong
and rigid forms.
-
See
nylon and Terylene
- COMPARISON OF THERMOPLASTICS and THERMOSETS
and a mention of FIBRES
-
In thermosoftening plastics
like poly(ethene), poly(propene) or poly(chloroethene) PVC, because the
inter-molecular attractive forces between the chains are weak, the plastic softens when heated and
hardens again when cooled. See also
addition
polymers page.
- It also means the polymer molecules can slide
over each other especially when heated to their relatively low
softening/melting points.
- This means they can be easily stretched or moulded into any
desired shape.
- They are examples of thermoplastics (thermosoftening
plastics), because they can be heated to make them softer - more
plastic, reshape it e.g. in an injection mould system, and on cooling the
plastic object retains its new shape - bottle, bowl, toy etc.
- However it is possible to manufacture
and process plastics in which the polymer chains are made to line up.
This greatly increases the intermolecular forces between the 'aligned'
polymer molecules and strong fibre strands of the plastic can
be made.
- Examples: The addition polymer poly(propene)
and the condensation polymers nylon and Terylene.
-
Thermosoftening
polymers like poly(ethene) and poly(propene) consist of individual, tangled
polymer chains and melt relatively easily when they are heated. This
contrasts with thermosetting polymers consist of polymer chains with strong
cross-links between them and so they do not melt when they are heated.
-
When a
thermosetting plastic
is
formed you not only get polymerisation to form long molecules, you also get
chemical bonds formed between various points in one polymer chain molecule across
to another polymer molecule.
- These extra bonds are called
cross-links
and
hold the linear polymer chains together in a much more rigid structure.
- These cross links do not
usually occur in the simpler addition polymerisations when thermoplastics
like poly(ethene) and PVC are made.
- Commercially, many thermosets consist of a
partially polymerised (but not cross-linked) resin, which contains a
cross-linking agent and a catalyst, so that when the mixture is exposed to
air or a the mixture warmed, cross-linking polymerisation occurs and the
hard thermoset is formed. This type of mixture is used to make fibre-glass
reinforced structures e.g. light car bodies or the hulls of sailing boats
and canoes.
-
These extra cross-linking
covalent bonds formed between adjacent chains of the polymers change
the physical properties considerably and thermoset polymers have much
higher high melting points (giving greater heat resistance and thermal stability)
as well as greatly
increased strength and rigidity.
- Compared to thermosoftening plastics, thermoset
polymers do not soften or melt and only
break down and degrade at much higher temperatures compared to the softening/melting points
of thermoplastics described above.
- Thermosets are harder, more
rigid/stiffer and not as easily bent or stretched, in fact they can
be quite brittle and almost impossible to stretch (not very
elastic!).
- Note that thermosets type polymers can be
formed at room temperature, heating may not be required.
- Many super glues form this kind of
structure.
- However, you have to get it right first time
because thermosetting polymers cannot be softened with heat and therefore
cannot be stretched or re-shaped, but the advantage is that thermosets are
much more heat resistant than thermoplastics.
- But these cross-linked thermoset polymers
are much more rigid (e.g. can't be stretched) and stronger
material (though they can be brittle) and not as flammable as most
thermoplastics.
- On heating them strongly they do NOT melt, but
tend to char, gradually giving off gases.
-
-
A simple diagram of the
polymer molecules in the three different situation.
-
Thermoplastic:
The polymer molecules tend to be randomly jumbled
up, but no cross-linking bonds.
-
Fibres:
Fibre molecules are thermoplastic molecules but
manufactured in such a way to get the 'molecules more lined up' to
increase intermolecular forces between the long molecules, and this
increases the strength of the fibre, but no cross-linking bonds are
formed.
-
Thermosets:
Their great strength and very rigid structure
derives from the strong cross-links between the polymer strands.
These cross-links are full chemical covalent bonds, NOT the much
weaker intermolecular forces/bonding in thermoplastics.
-
In thermoplastics you have
intermolecular bonding (weak attractive forces) between polymer molecules.
-
In thermosets you have
intramolecular chemical bonding (very strong attractive
forces) between the adjacent polymer molecule chains.
-
Heat resistant polymers are
usually thermosets e.g. like melamine resin (plastic plates), but even
thermoplastics like poly(propene) can be used in hot situations e.g. plastic
electric kettles.
- Examples of Thermosets:
- Melamine (used in furniture), Bakelite
(was used for electrical fittings, a horrible brown colour but a good
insulator, not used now?), Formica (table tops) and some super
glues are examples of thermosetting polymers.
- See also ....
TOP OF PAGE
and sub-index
11B.
More on
Other Synthetic Polymers
-
macromolecules
SYNTHETIC FIBRES like NYLON and TERYLENE -
condensation polymers
Condensation
polymerisation involves linking lots of small
monomer molecules together by eliminating a small molecule. This is
often water from two different monomers, a
H from one monomer, and an
OH
from the other, the 'spare bonds' then link up to form the
polymer
chain plus H2O.
In addition polymerisation there is
only one monomer molecule with a double bond and one product, the polymer,
and the linking occurs via a reactive double bond.
Condensation polymerisation
involves monomers
with two functional groups (one at each end of the molecule). When
these types of monomers react, they join together (polymerise), small
molecules such as water are eliminated in the process, and so the
reactions are called condensation reactions, hence the process is
called condensation polymerisation.
The simplest polymers are made from two
different monomers with two of the same functional groups on each
monomer.
-
Terylene (a polyester) and nylon are
good for making 'artificial' or 'man-made' fibres used in the clothing and rope
industries.
- In the manufacturing process the polymer chains are made to
line up.
- This greatly increases the intermolecular forces between the
'aligned' polymer molecules and strong fibre strands of the
plastic can be made.
- A
polyester
can be made from ethane
diol (an alcohol with two hydroxy groups two -OH's) and hexanedioic acid
(a carboxylic acid with two -COOH groups, a dicarboxylic acid).
- These are the two starting monomers prior to
polymerisation and both must have a reactive group at each end - and a
different functional group that can react with the other.
- The ethanediol monomer molecule
HO-CH2-CH2-OH
- This type of molecule is called a diol,
because it has two alcohol groups -OH.
- The hexanedioic acid molecule monomer molecule
HOOCCH2CH2CH2CH2COOH
- This type of molecule is called a
dicarboxylic acid, because it has two carboxylic acid groups -COOH.
- Alcohols react with carboxylic acid to form
esters with the elimination of water.
- In this case the ester linkage is formed at
both ends of each molecule with the elimination of water molecules.
- Polyesters are condensation polymers because of
how they are formed - by this condensation reaction that eliminates a
small molecule to form the
ester bond between the monomers.
Diagram to explain how a diol (alcohol)
and a dicarboxylic acid condense together to give an ester linkage.
Here just one of
each monomer have condensed together to make a bigger molecule -
the water is eliminated as the new linking covalent bond is
formed - an ester
bond.
BUT, at each end of
this molecule, the functional group (alcohol -OH, on left) can
link with the other functional group (carboxylic acid, -COOH, on
right) to create an even bigger molecule - eventually, a long
chain polyester polymer will form.
- Where n is the very large number of monomer
molecules, the condensation polymerisation of ethane diol and
hexanedioic acid can be represented as ...
n HO-CH2-CH2-OH
+ n HOOCCH2CH2CH2CH2COOH
===> -(-CH2-CH2-OOC-CH2CH2CH2CH2-COO-)n-
+ 2n H2O
or more simply: n HO-[][]-OH
+ n HOOC-[][][][]-COOH
==> -(-[][]-OOC-[][][][]-COO-)n-+
2n H2O
[][]
and [][][][]
represent the rest of the molecules, and n is a very large number
!
-
Terylene (a polyester)
is formed by
condensation polymerisation and the simplified structure of Terylene
can be represented as
-
3 units as
partially displayed formula
More advanced displayed formula
representations of Terylene and its formation
-
Nylon (a polyamide)
is formed by condensation polymerisation, the structure of nylon represented
below where the rectangles represent the rest of the carbon chains in each
unit.
- Nylon is made polymerising a dicarboxylic acid
and a diamine with the elimination of water.
- Both monomers have the same functional
group at each end, hence di.... in their names.
Diagram showing the formation of the
polyamide link as a water molecule is eliminated when the
carboxylic acid group in one monomer, bonds with amine group of the other
monomer.
In
this case two amino acids have a formed the simplest possible polypeptide -
a simple dipeptide.
Note
*
that at each end of the molecule, the
amine
group (-NH2,
on left) and the
carboxylic acid group (-COOH,
on right) can both form a bond with another diamine molecule by
further elimination of water molecules.
Diagram to explain how a diol (alcohol)
and a dicarboxylic acid condense together to give an ester linkage.
Here just one of
each monomer have condensed together to make a bigger molecule -
the water is eliminated as the new linking covalent bond is
formed.
BUT, at each end of
this molecule, the functional group (alcohol -OH, on left) can
link with the other functional group (carboxylic acid, -COOH, on
right) to create an even bigger molecule - eventually, a long
chain polyester polymer will form.
- n HOOC-[][][][]-COOH
+ n H2N-[][][][]-NH2
==> -(-OC[][][][]-CONH-[][][][]-NH-)n-+
2n H2O
-
3 units
as partially displayed formula.
-
is the displayed formula of a diamine.
-
is the displayed formula of a dicarboxylic acid.
- This is the same linkage
(-CO-NH-) that is found in linked amino acids in naturally occurring
macromolecules called polypeptides and proteins, where it is called the 'peptide'
linkage.
- Nylon-6,6
-
Making Nylon-6,6 in the
laboratory
- In the 1st beaker, make a solution of
1,6-diaminohexane in water.
- In a 2nd beaker, dissolve
1,6-hexanedioyl dichloride in a suitable organic solvent - it must be
one that does not mix with water - an immiscible liquid like the organic
solvent 1,1,2-trichloroethane.
- Pour one solution on top of the other,
and nylon is formed at the interface of the two solutions.
- With a glass rod, you can extract a blob
of nylon on the end, lift it up carefully and twist the glass rod around
and wind up a steady 'mushy' thread of nylon..
- At GCSE level you don't need to write an
equation, but you might be expected to recognise the condensation
polymerisation reaction AND the small molecule, hydrogen chloride HCl, is eliminated. The equation is:
-
n HOOC-(CH2)4COOH
+ n H2N-(CH2)6-NH2
==> -(-OC(CH2)4-CO-NH-(CH2)6-NH-)n-
+
2n H2O
- Unless you are studying chemistry at an advanced
level, you don't have to no why its called
Nylon-6,6, but it's because both monomers have a chain of 6 carbon
atoms!
Specific uses of Nylon
Nylon is a tough strong material that
doesn't melt until ~250oC.
Nylon is strong enough to be used to make
mechanical parts for machines including bearings and
rollers.
Nylon has a high electrical resistance and
is used to make safe switches operating electrical circuits.
See also
Extra advanced Level notes
on Nylon structure and synthesis
A
comparison of addition polymerisation and condensation
polymerisation |
|
Addition
polymerisation |
Condensation
polymerisation |
Monomers used |
One type only, the
monomer has an alkene >C=C< double bond |
(i) Two different
monomers, each has two of the different functional groups
at the ends of the molecules that
condense together to form the bond
OR (ii) A single
monomer molecule with both functional groups, one at
each end, by which they can link together |
Products |
Only the polymer itself |
Two products - the polymer
and a small molecule eliminated in forming the bond
between the two different functional groups |
Functional groups involved |
Only the double bond (C=C)
of the alkene group |
Two reactive groups at each
end of the polymer molecule e.g. -OH, -COOH, -NH2 |
TOP OF PAGE
and sub-index
11C. Examples of
NATURAL POLYMERS,
their structure, function and uses
- Note that silk and cotton fibres (strong
fibres for fabrics), rubber (for tyres and elastic objects) are very
useful natural materials that have been harvested for many years from
the natural world.
-
Silk
has been used as a
clothing and decorative fabric for thousands of years, and, like sheep's
wool, is essentially a protein polymer material.
-
Rubber
has been used for
centuries as a natural elastic polymer, but it has been replaced by
synthetic polymers like neoprene.
-
Wood
is an extremely useful construction
material, and is mainly a polymer mixture of cellulose (a natural polymer of
glucose) and lignin (with a rigid cross-linked polymer structure).
- The valuable crop of
cotton (for
fabrics) also has a molecular structure based on cellulose, in fact it is
the purest form of cellulose that occurs naturally and forms strong
useful fibres.
-
Starch,
cellulose and sugars are all carbohydrate
molecules
- Sugars are small molecules, but starch and
cellulose are natural
condensation polymers of sugars based on the condensation
polymerisation of small sugar molecules like glucose.
- Starch and sugars are used in the food industry,
starch being a polymer based on sugar.
- See
Natural molecules - carbohydrates
- sugars - starch, DNA for more details
-
Amino acids have two functional groups from
which peptides and proteins are made.
- This involves a condensation polymerisation in
the biochemistry of living systems.
- The carboxylic acid group -COOH and
the amino or amine group -NH2
- The simplest one is aminoethanoic acid (glycine)
H2N-CH2-COOH
- Proteins are naturally occurring polymers
based on amino acids.
- Amino acids can undergo condensation
polymerisation via the two functional groups to form peptides,
and all sorts of combinations of amino acids produce the huge variety of
proteins found in living systems.
-
For glycine the condensation polymerisation to
give a glycine peptide can be shown as ..
- n H2N-CH2-COOH
===> -(NH-CH2-COO-)n- + 2n H2O
- where n is a very large number, with the
elimination of 2n water molecules, one from each link at either end of
the glycine monomer molecule.
- The equation illustrates the structure if only
one amino acid is used, in reality, proteins are very complex using a
variety of around 20 different amino acids, each with its own unique
structure, leading to lots of different proteins with their own unique
structure. Think of all the different tissues in your own body!
- For more details see
Amino acids,
proteins, polypeptides, enzymes & chromatography for more
details.
-
DNA (deoxyribonucleic acid)
- DNA is a very large molecule essential for life
and the basis of genetic chemistry in living systems.
- In a cells biochemistry the DNA encodes genetic
instructions for the development and functioning of all living organisms
and viruses.
- Most DNA molecules are two polymer chains made
from four different monomers called nucleotides.
- Two strands of the DNA molecule are coiled
together in the form of a double helix.
- For more details see
DNA and RNA structure and Protein Synthesis gcse
biology revision notes
- -
See also
A survey of the properties and
uses of a wide range of materials
TOP OF PAGE
and sub-index
|
11D An
exercise in choosing a plastic for a
particular use
(this section is repeated on the other
GCSE polymer notes page)
How we use polymer compositions
depends on their properties, some are quoted in the data table
below
So, below is a decision making
exercise on choosing a plastic for a particular job!
Note: NOT ALL the properties
are necessarily relevant to make the decision.
At the moment A to F match
questions (a) to (f) once only, but I may add further questions!
This exercise should provide a
good challenge and discussion for a class, any feedback comments
appreciated.
Polymer product |
Production cost |
Chemical resistance |
Melting point |
Strength (rigidity) |
Transparency |
can be made
into fibres? |
A |
high |
high |
high |
high |
good |
no |
B |
low |
low |
high |
moderate |
poor |
no |
C |
low |
low |
low |
low |
opaque |
yes |
D |
low |
low |
low |
low |
poor |
no |
E |
high |
low |
high |
very high |
opaque |
yes |
F |
low |
high |
high |
high |
poor |
no |
(a) Which
plastic could be used as for disposable tableware like plates
for hot meals or coffee cups?
(b) Which
plastic could be used as a moving plastic component in a
machine?
(c) Which
plastic could used as containers for high volume production line
of acids or alkalis?
(d) Which
plastic could be used as laboratory volume measuring instrument
e.g. a syringe or measuring cylinder
(e) Which
plastic is suitable for clothing fabrics?
(f) Which
plastic would be used for super-market carrier bags?
Answers near the
end of the page
-
Plastics are widely
used in the manufacture of cars
and other road vehicles because
they are cheap to make of varied composition for a wide variety of
uses, they are light, durable and can be dyed any colour, they can
be flexible or rigid and so can be used for e.g. used for internal
fittings e.g. dashboard cover, floor covers (can be rubber too),
door coverings, transparent and coloured covers over headlights and
brake lights, and the insulating sheathing for all the electrical
wiring.
-
See also
A survey of the properties and
uses of a wide range of materials
TOP OF PAGE
and sub-index
LINKS
See also
Extra advanced Level notes
on Nylon structure and synthesis
and extra
Advanced Level notes of
poly(alkene) addition polymers
GCSE/IGCSE/O Level Oil Products & Organic Chemistry INDEX PAGE
See section 7. for full details on
addition polymers
ALL my Advanced
A Level Organic Chemistry revision notes

Multiple Choice Quizzes and Worksheets
KS4 Science GCSE/IGCSE m/c QUIZ on Oil Products
(easier-foundation-level)
KS4 Science GCSE/IGCSE m/c QUIZ on Oil Products
(harder-higher-level)
KS4 Science GCSE/IGCSE m/c QUIZ on other aspects of Organic Chemistry
and
3 linked easy Oil Products gap-fill quiz worksheets
ALSO gap-fill ('word-fill') exercises
originally written for ...
... AQA GCSE Science
Useful products from
crude oil AND
Oil, Hydrocarbons
& Cracking
etc.
... OCR 21st C GCSE Science
Worksheet gap-fill C1.1c Air
pollutants etc ...
... Edexcel GCSE Science
Crude Oil and its Fractional distillation
etc ...
... each set are interlinked,
so clicking on one of the above leads to a sequence of several quizzes
|
Answers to the Choosing a Plastic for a
Particular Use Exercise in decision making
(a) Plastic B,
to be disposable it must be cheap, chemical resistance
doesn't matter (only in contact with food/drinks once), needs to be heat
resistant, transparency doesn't matter?, needs to be reasonably rigid.
(b) Plastic E,
firstly, it must be very strong to withstand the physical
movement and friction in a working machine, it withstand heat from friction,
chemical resistance need not be high, high cost acceptable for a specialised
non-disposable part of a machine.
(c) Plastic F, needs to be
reasonably cheap but heat and chemical resistant.
(d) Plastic A,
it needs to be transparent to read the calibration marks
accurately, it needs to be chemically and heat resistant to safe to use in the
laboratory, it needs to be rigid to retain its accuracy, the high cost would be
acceptable for a valuable measuring instrument in the laboratory, its not
disposable.
(e) Plastic C,
most important that it can be made into fibres, chemical and
heat resistance is the responsibility of the owner/wearer!, needs to opaque or
it becomes a 'see through'!
(f) Plastic D,
the plastic needs to cheap, flexible and disposable (low
cost), heat and chemical resistance are not important - responsibility of user!
Keywords and phrases: : This further page on
macromolecules-plastics describes the difference in formation of addition
polymers like poly(chloroethene)/PVC and condensation polymers like Terylene and
Nylon, all of which are thermosoftening polymers. The properties of
thermosoftening polymers (thermoplastics) are compared with thermosetting
polymers (thermosets). These revision notes on plastics and fibres should prove
useful for the new AQA, Edexcel and OCR GCSE (9–1) chemistry science courses.
These revision notes on the comparison of the structure and properties of
thermoplastic polymers, thermosets and fibres should prove useful for the NEW AQA GCSE chemistry,
Edexcel GCSE chemistry & OCR GCSE chemistry (Gateway & 21st Century) GCSE (9–1),
(9-5) & (5-1) science courses.
TOP OF PAGE
and sub-index
Notes information to help revise
KS4 Science Additional Science Triple Award Separate Sciences Chemistry revision
notes for GCSE/IGCSE/O level Chemistry Revision-Information Study Notes for
revising AQA GCSE Science AQA GCSE Chemistry, Edexcel
GCSE Science, Edexcel GCSE Chemistry, OCR 21st Century Science Chemistry, OCR Gateway Science
chemistry, WJEC/CBAC
GCSE science-chemistry CCEA/CEA GCSE science-chemistry
(and courses equal to US grades 8, 9, 10)
KS4 Science comparing thermoplastics thermosets
fibres properties uses nylon polyester Terylene GCSE chemistry guide notes on
comparing thermoplastics thermosets fibres properties uses nylon polyester
Terylene for schools colleges academies science course tutors images pictures
diagrams of apparatus for comparing thermoplastics thermosets fibres properties
uses nylon polyester Terylene investigations word balanced symbol equations of
comparing thermoplastics thermosets fibres properties uses nylon polyester
Terylene science chemistry revision notes on comparing thermoplastics thermosets
fibres properties uses nylon polyester Terylene revising the chemistry of
comparing thermoplastics thermosets fibres properties uses nylon polyester
Terylene help in chemical understanding of comparing thermoplastics thermosets
fibres properties uses nylon polyester Terylene description of comparing
thermoplastics thermosets fibres properties uses nylon polyester Terylene
experiments for chemistry courses university courses in chemistry careers in
chemistry jobs in the chemical industry laboratory assistant apprenticeships in
chemistry technical internship in chemistry IGCSE chemistry comparing
thermoplastics thermosets fibres properties uses nylon polyester Terylene USA US
grade 8 grade 9 grade10 comparing thermoplastics thermosets fibres properties
uses nylon polyester Terylene chemistry gcse chemistry revision free detailed
notes on structure properties uses of condensation polymers nylon Terylene to
help revise igcse chemistry igcse chemistry revision notes on structure
properties uses of condensation polymers nylon Terylene O level chemistry
revision free detailed notes on structure properties uses of condensation
polymers nylon Terylene to help revise gcse chemistry free detailed notes on
structure properties uses of condensation polymers nylon Terylene to help revise
O level chemistry free online website to help revise structure properties uses
of condensation polymers nylon Terylene for gcse chemistry free online
website to help revise structure properties uses of condensation polymers nylon
Terylene for igcse chemistry free online website to help revise O level
structure properties uses of condensation polymers nylon Terylene chemistry how
to succeed in questions on structure properties uses of condensation polymers
nylon Terylene for gcse chemistry how to succeed at igcse chemistry how to
succeed at O level chemistry a good website for free questions on structure
properties uses of condensation polymers nylon Terylene to help to pass gcse
chemistry questions on structure properties uses of condensation polymers nylon
Terylene a good website for free help to pass igcse chemistry with revision
notes on structure properties uses of condensation polymers nylon Terylene a
good website for free help to pass O level chemistry
TOP OF PAGE
and sub-index
|
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
Website content © Dr
Phil Brown 2000+. All copyrights reserved on revision notes, images,
quizzes, worksheets etc. Copying of website material is NOT
permitted. Exam revision summaries & references to science course specifications
are unofficial. |
GCSE/IGCSE/O Level Oil Products & Organic Chemistry INDEX PAGE
See section 7. for full details on
addition polymers
ALL my Advanced
A Level Organic Chemistry revision notes

|