This document provides an introduction to polymers and rubbers. It defines polymers as large chains of repeating molecules or monomers that are attached end to end. Polymers are classified as natural or synthetic. Natural rubber is a polymer of isoprene that comes from rubber trees, while synthetic rubbers are manufactured polymers that act as substitutes for natural rubber. The document discusses different types of synthetic rubbers and their properties, as well as uses of both natural and synthetic rubbers. Vulcanized rubber is also introduced as a hardened type of rubber produced through sulfurization.

1. Introduction of Polymers &Rubbers
R.Mamani
Assistant Professor
Department of Chemistry
Bon Secours college for women
Thanjavur

2. Introduction
Definition
Classification
Types of Polymerization
Rubbers

3. The word polymer comes from the Greek words “poly
+mere's poly=many Mers=Parts
A Polymer consists of a large chain of repeating
molecules (monomers) that are attached in
an end to end fashion
Polymers typically consist of between 20,000 and
40,000 individual monomers

4. A long molecule made up from lots of small
molecules called monomers.
Polymer is the combination of large number of
repeating units of monomer
The process of reaction monomer molecules together
in a chemical reaction to three dimensional network
chain is known as polymerisation
A + A + A + A  -A-A-A-A-
eg poly(ethene) polyvinyl chloride PVC

13. Rubber is a natural polymer of Isoprene (usually cis-1,4-polyisoprene).
 It is hydrocarbon polymer occurring as milky latex in the sap of various
plants and can also be made synthetically.
A small percentage (about 5%) of other materials like proteins, fatty acids,
resins and inorganic materials (salts) are also present in natural rubber.
Rubber, as mentioned earlier too, can also be made artificially or
synthetically.
The type of rubber which is produced artificially is called synthetic rubber.
 Rubber can be defined as a sticky, elastic solid which is produced from a
milky liquid known as latex obtained from various types of rubber trees
There are basically two broad categories into which the rubber types can be
placed.
These are- Natural Rubber and Synthetic Rubber.
Sometimes vulcanized rubber is also taken to be a type of rubber. Lets know
about all these types of rubber.

14.  There are basically two broad categories into which the rubber types can be
placed.
 These are- Natural Rubber and Synthetic Rubber. Sometimes vulcanized
rubber is also taken to be a type of rubber.
 Lets know about all these types of rubber.
 Synthetic Rubber
 Any kind of artificial elastomer (a polymer) is called synthetic rubber.
 An elastomer can be defined as a material having the property of elasticity.
 Thus, the type of rubber made from chemicals to act as the substitute for
natural rubber is the synthetic rubber.
 There are various types of polymers used for making synthetic rubber
types.
 Due to this, different types of synthetic rubbers have different properties
that are tailored for specific needs of rubber products industries.

15. S.No
Rubber type Benefits Limitations
Typical
applications
1
Natural Rubber
Widest range of
hardness
Very strong &
naturally self
reinforcing
Good compression
set
Good resistance to
inorganic chemical
Lack of oil and
organic fluids
resistance
Max temperature
75 - 100°C
Poor ozone
resistance
Sealing and shock
absorption
Conveyor belting
Truck tyres
2
SBR
Good physical
strength
Good tear and
abrasion resistance
Poor oil and fuel
resistance
Poor weather
resistance
Non-mechanical
high volume
products
Shoe soles and car
tyres
3
Polybutadiene
Good abrasion
resistance
Low glass transition
temperature
High resilience
Very poor ozone
resistance
Tyres
Conveyor belts
Polystyrene and
ABS modification

16.  Synthetic rubber is used as a substitute for natural rubber in many cases.
 Depending on the chemicals added and the properties associated with it, the
synthetic rubber can be as hard as a bowling ball or as resilient as a rubber band or
as soft as a sponge.
 When improved material properties are required, synthetic rubber is considered.
 Butadiene Rubber (BR),Butyl Rubber (IIR),Isoprene Rubber (IR),Neoprene
 Uses of Rubber
 Rubber can be used for various rubber and across various platforms, few of them
are mentioned below;
 It is used for lining chutes, bins and industrial mixers. Because of its water-proof
and resilient property it can be made into a good insulator.
 In clothing industry, it can be used as wetsuits and expandable clothes such as gym
and cycling shorts etc.
 Rubbers are also used for flooring purposes it gives padding and prevents fatigue
along with being waterproof and slip-resistant.
 In automobile industry, its use can be witnessed in tires, padding in brakes, airbags,
seats, and roof etc.

17.  Vulcanized type of rubber material is less sticky and has superior
mechanical properties than natural rubber.
 The hardness of vulcanized rubber depends upon the amount of
sulphur used during the process and the degree of this hardness
determines as to which industry could use the vulcanized rubber for
making various products.
 For example, if 5% of Sulphur is used during vulcanization, it will
produce tyre rubber. Ebonite is made by adding 20 to 25% sulphur
and battery case rubber is made by adding 30% of Sulphur during
vulcanization.
 Other products made from hard vulcanized rubber include bowling
balls and saxophone mouth pieces etc.
 Less harder vulcanized rubber is used for making various
household and industrial rubber products like shoe soles, hoses etc.

21. THANK YOU