Kerala Technical Board-Polytechnic College Engineering Chemistry-II Second Semester Module 3- Basic organic chemistry and polymers

1. By MUHAMMED SALMAN FARISH TP
Email: tpmsalman@gmail.com

3. Organic chemistry ?
Organic chemistry is the branch of chemistry which
deals with the study of hydrocarbons and its derivatives.
Compounds containing carbon and hydrogen are called
hydrocarbons. Except oxides of carbon, carbonate and
hydrogen carbonate, they are under the branch of inorganic
chemistry.
Examples for organic compounds; plastics, protein, rubber,
methane, acetic acid ( vinegar ).
Inorganic compounds include the compounds of all
other elements except Carbon and hydrogen.

4. Uniqueness of Carbon
1. Carbon can form ring and chain compounds with other
carbon atoms – called catenation.
2. Carbon can make multiple bonds (single, double and
triple bond ) at a time with other carbon atoms.
3. Since carbon has a valency of four, it is capable of
bonding with four other atoms of carbon or atoms of
some other mono-valent element.
4. Carbon showing a number of allotropes like diamond,
graphite, fullerene etc…

5. Hydrocarbons
Saturated Unsaturated
1. Alkanes 1. Alkenes
2. Alkynes

6. Alkanes (single bond betweenCarbon atoms)
Number of
C atoms
Name Molecular
formula
structure
1 Methane C1H4 CH4
2 Ethane C2H6 CH3-CH3
3 Propane C3H8 CH3-CH2-CH3
4 Butane C4H10 CH3-CH2-CH2-CH3

7. Alkenes (double bond between Carbon atoms)
Number of
C atoms
Name Molecular
formula
Structure
2 Ethene C2H4 CH2=CH2
3 Propene C3H6 CH3-CH=CH2
4 Butene C4H8 CH2=CH-CH2-CH3
4 2-butene C4H8 CH3-CH=CH-CH3

8. Alkynes (triple bond between Carbon atoms)
Number of
C atoms
Name Molecular
formula
Structure
2 Ethyne C2H2 HC≡CH
3 Propyne C3H4 CH3-C≡CH
4 Butyne C4H6 CH≡C-CH2-CH3
4 2-butyne C4H6 CH3-C≡C-CH3

9. Tests to identify saturated and
unsaturated compounds?
Saturated compounds Unaturated compunds
Reaction with KMnO4 : exist
the pale blue colour of KMnO4
as before.
Reaction with KMnO4 :
disappearing the pale blue
colour of KMnO4.
Reaction with Bromine water:
yellow colour of bromine water
existed as it was.
Reaction with Bromine water:
yellow colour get disappearing
It will not undergo addition
reaction but undergo
substitution reaction.
These will Undergo addition
reactions

10. Functional group
 Functional groups are atoms or groups coming after
replacing an Hydrogen atom from alkanes. eg; alcohols,
aldehyde, ketones etc…
 Depending on the functional groups present in
compounds, their properties may be varied.
Some of the functional groups and their naming
listed below

11. Functional groups
Name of functional
group
Structure Ending of IUPAC
name
Alcohol -OH ol
Aldehyde -CHO al
Carboxylic acid -COOH oic acid
Alkoxy group (ether) -O- alkoxyalkane
Amines -NH2 amine
Ketones - CO amine
Ester -COO oate

12. Polymers
 Polymers are very large molecules having high molar
mass and are formed by the combination of a large
number of simple molecules called monomers.
eg; polyethene, polystyrene, polyester.
 The process of formation of polymers from respective
monomers is called polymerisation.
 Poly means “more number” and mer means “unit”

13. Classification of polymers
Classification
based on source
Natural polymers
eg; rubber, proteins, cellulose
Semi synthetic polymers
Eg; Cellulose derivatives
Synthetic polymers
Man made polymers
Eg: polythene, poly
styrene,PVC etc

14. Classification based on
structure
Linear polymers.
Long and straight
chains of polymers.
E.g. high density
polythene, polyvinyl
chloride
Branched polymers.
Linear chains having
some branches. E.g. low
density polythene
Cross linked
polymers.
contain strong
covalent bonds
between various
linear polymer
chains. Eg;
bakelite

15. Classification based on the type of
monomers
Homopolymers:
These are polymers
containing only one type of
monomer unit.
E.g.: polythene, polystyrene.
polypropene etc
Copolymers
These are polymers
containing different types of
monomer units.
E.g.: Polyesters like glyptal,
terylene etc. poly amides like
Nylon-6, Nylon-6,6 etc.

16. Classification based on the
mode of polymerization
Addition
polymerisation
By the addition of
monomers, eg; polyethene,
polypropene
Condensation
polymerisation
Elimination of small
molecules such as water,
eg, Nylon 6,6 and nylon 6

17. Classification based on the
Molecular Forces
Elastomers Fibres Thermo
polymers
Thermosettin
g polymers

18.  Elastomers: These are rubber – like solids with elastic
properties. It contain weak intermolecular forces (van der
Waal’s force). So they can be stretched. A few ‘cross links’
are formed in between the chains. E.g. buna-S, buna-N,
neoprene, etc.
 Fibres: Fibres are the thread forming solids which possess
high tensile strength and high modulus. Here the different
polymer chains are held together by strong intermolecular
force like hydrogen bonding, they have close packed
structure and are crystalline in nature. Eg:-Nylon- 6,6 and
nylon-6

19.  Thermoplastic polymers:
These are the linear or slightly branched long chain
molecules. They can be repeatedly softening on heating and
hardening on cooling. examples are polythene, polystyrene,
polyvinyls, etc…
 Thermosetting polymers:
These are cross linked or heavily branched
molecules. On heating they undergo cross links and become
infusible. Eg:bakelite,glyptal

20. Rubber
 Natural rubber:
 It is a linear polymer of isoprene (2-methyl-1, 3-
butadiene) and is also called as cis-1, 4 - polyisoprene.
H2C = C – CH = CH2
 The various cis-polyisoprene chains are held together by
weak van der Waals forces and has a coiled structure.
Thus, it can be stretched like a spring and exhibits elastic
properties.
CH3
|

21. Vulcanisation and its merits
 Vulcanisation of rubber; To improve the physical
properties of natural rubber, it is heated with sulphur and
an appropriate additive at a temperature of 373 to 415 K.
This process is called vulcanisation. On vulcanisation,
sulphur forms cross links between the different poly
isoprene units and thus the rubber gets stiffened.
 Synthetic rubbers: These are either homopolymers of 1,
3 - butadiene derivatives or copolymers of 1, 3 - butadiene
or its derivatives with another unsaturated monomer.
examples are: Neoprene (polychloroprene), buna –S and
Buna-N.

22. Some commercially important
polymers
1. Polythene
nCH2=CH2 → [ CH2-CH2 ] n
Ethene Poly ethene
Uses:toys flexible pipes, dustbins, bottles & pipes
2. Polypropene
nCH2=CH-CH3 → [ CH2-CH2-CH2 ] n
Propene Polypropene
Uses: Manufacture of ropes, toys, pipes, fibres, etc

23. 3. Polystyrene
nCH2=CH → [ CH2-CH] n
Styrene Polystyrene
 uses: As insulator, wrapping material,
4. Polyvinyl chloride (PVC)
n CH2=CH → [CH2-CH] n
vinyl chloride Polyvinyl chloride
 Uses :Manufacture of rain coats, hand bags, vinyl flooring.
|
C6H5
C6H5
|
|
Cl
|
Cl

24. 5. Neoprene
Uses : manufacture of conveyor belts, gaskets, hoses
6. Teflon
n CF2=CF2 [ CF2-CF2]
Tetraflouroethene Teflon
Uses:to make non- stick surface coated utensils and oil seals
catalyst
High pressure

25. 7. Buna –N
Uses : to make oil seals and tank lines
8. Buna – S
n CH2=CH-CH=CH2 + n CH2=CH → n [CH3-CH=CH-CH2-CH2-CH-]
1,3-butadiene Styrene Buna – S
Uses : manufacture of auto tyres and footwear components
C6H5
||
C6H5

26. 9. Nylon 6,6
Adipic acid + hexamethylenediamene → Nylon6,6
Uses:to make sheets, bristles for brushes
10. Nylon 6
Uses : tyre cords, fabrics and ropes

27. 11. Bakelite
It prepared from phenol and formaldehyde. Used for making
combs, electrical switches, handles of utensils and computer
discs.

28. Refractories

29. Refractories
• Materials that can
withstand high
temperature without
softening and deformation
in their shape.
• Used for the construction
of furnaces, converters,
kilns, crucibles, ladles
etc…

30. Properties of refractories.
Infusible at
operating
temperature
Chemically inert
towards corrosive
gases, liquids etc.
Should not suffer
change in size at
operating temp
Should have
high
refractoriness
Should have high load
bearing capacity at
operating temp.

31. Properties of refractories.
• A good refractory should have low
 Porosity
 Thermal Spalling
 Thermal Expansion
 Electrical conductivity
 Have high refractoriness.
Refractoriness : “ It is the ability to withstand very high temp.
without softening or deformation under particular service
condition”.

32. Porosity
• All refractories contain pores, either due to manufacturing
methods or deliberately made( by incorporating saw-dust or
cork during manufacture).
• Porosity is the ratio of its pore’s volume to the bulk volume.
W – D
W - A( )XP = 100
Weight = W Weight = D Weight = A
Specimen
Submerged in waterDry SpecimenSaturated Specimen

33. Thermal spalling
 “Property of breaking,
cracking or peeling of
refractory material
under high
temperature”. It is Due
to ;
1. Rapid Change in
temperature
2. Slag penetration

34. Types of
refractories
Acid
refractories
Basic
refractories
Neutral
refractories

35. Acid refractories
 Acid refractories are those which are attacked by basic
slags. These are not affected by acid slags and hence, can
be safely used where the environment is acidic. Examples
of acid refractories are:
Silica (Most acidic).
Semi - Silica.
Alumino - Silicate Refractories.

36. Basic refractories
 Basic refractories are those which are attacked by acid
slags. Since they do not react with basic slags so, these
refractories are of considerable importance for furnace
linings where the environment is basic for example, in
furnace for non-ferrous metallurgical operations.
Examples of basic refractories are:
1. Magnesite.
2. Mag - Chrome.
3. Chrome - Mag.
4. Dolomite.

37. Neutral Refractories
 These are the refractories that are neither attacked by acid
nor by basis slags. Examples are:
1. Graphite (Most inert).
2. Chromites.

38. Glass
 Glass is a mixture of silicates, Or
 it is amorphous, hard, transparent , brittle super cooled
liquid with infinite viscosity formed by fusing a mixture
of sodium carbonate, calcium carbonate and silica.
Types of glasses
1. Soda glass
2. Borosilicate glass
3. Safety glass
4. Insulating glss

39. Types of glasses
 Soda glass
Components; Silica, sodium carbonate, calcium carbonate
Uses; for the manufacturing of bottles, window glasses, jars
 Boro silicate glass
Components; Silica, borax, alumina ( sodium aluminum
boro silicate)
Uses; laboratory glasswares( burette, pipette, conical flask),
telivison picture tube.

40. Safety glass
 Prepared by placing a thin
layer of plastic sheet
between two glass sheets.
 When breaks, it will not
make sharp edges and will
not fly apart in
atmosphere.
uses; as wind shields in
automobiles and in aero
planes.

41. Optical fibers
 It is a transparent, flexible fiber made by drawing glass to
a diameter slightly less than that of human hair. It can
transmit signals between the two ends of the fiber by the
result of total internal reflection. It can transmit signals
effectively with out losing strength of the signal.
 Uses;
1. communication transmission over long distances.
2. as optic sensors to measure strain, temperature,
3. as light guides
4. in imaging optics