3. GROUP MEMBERS
We are going to discuss about elastomers.
Nusrat-E-Noor Annana
Id-21224107007
Intake-33
Nova Islam
Id-21224107008
Intake-33
Md Shamim Khan
Id-21224107009
Intake-33
Presented to,
Md Yousuf Ali
Bangladesh University of Business and
Technology(BUBT)
3
4. Elastomers are polymers that have elastic
properties, which means they can stretch and
return to their original shape.
They are commonly used in a wide range of
industries due to their unique properties.
Elastomers can be found in various forms such as
rubber, latex, silicone, and many more.
INTRODUCTION
4
5. HISTORY
• After world war II , advances in
polymer technology brought to
the dental profession a group of
synthetic rubbery materials called
ELASTOMERS.
• Polysulfides at the beginning of
the fifties (1950), were the first
elastomeric impression material
used in the world of dentistry.
5
6. 1891 John Boyd Dunlop invents the first practical
pneumatic tire.
1909
1950-1960
1970-1980
Fritz Hofmann develops synthetic rubber, which
becomes increasingly important during World
War II when natural rubber supplies are limited.
The popularity of synthetic rubber continues to
grow, as it is used in a wide range of products
including tires, hoses, gaskets, and electrical
insulation.
The development of new elastomer compounds
and the increasing use of composite materials
lead to new applications for rubber in
aerospace, defense, and sports equipment.
HISTORY 6
7. Properties of elastomers-
They are flexible and can bend.
It is practically impossible to crack it.
Low creep resistance.
They are insoluble.
There are two types of elastomers-
Thermoplastic elastomers, are the
ones which can melt.
Thermosetting elastomers, are the
ones which cannot melt.
ELASTOMERS 7
8. They own their impressive elastic properties to these
features- 1. Molecules are tightly linked when
unstretched.
2. Degree of cross-linking is substantially less
than thermosets.
3. When stretched, the molecules are
forced to uncoil and straighten.
A
B
(A) Is an unstressed polymer (B) Is the same polymer under stress
CHARACTARISTICS 8
10. STRUCTURE
The structure of elastomers is characterized by the
presence of long, coiled chains of polymer
molecules that are interconnected by weak
forces such as Van der Waals forces, hydrogen
bonds, and entanglements.
The polymer chains in elastomers are typically
made up of monomers such as isoprene,
butadiene, or styrene. These monomers have a
double bond between carbon atoms that can be
easily stretched and deformed without breaking.
10
11. STRUCTURE
• The double bonds also allow for cross-linking between
chains, which helps to reinforce the structure of the
elastomer.
• In the absence of any external forces, elastomers exist in
a relaxed state, with the polymer chains coiled up
randomly. When an external force is applied, the polymer
chains uncoil and straighten out, allowing the elastomer
to deform.
• The weak intermolecular forces that hold the polymer
chains together allow the elastomer to return to its original
shape and size once the external force is removed.
11
12. APPLICATION
Seals and gaskets
• Used to make seals and gaskets because of
their ability to provide a tight seal even under
high pressures and temperatures.
They are used in various industries, such as automotive, aerospace, construction, and
manufacturing.
12
13. APPLICATION
Elastomers are used to make various
medical devices, such as catheters,
gloves, and prosthetics.
Medical devices
Elastomers are the main component of tires
because of their ability to provide good traction,
durability, and resistance to wear and tear. They
are used in various types of vehicles, such as cars,
trucks, airplanes, and bicycles.
Tires
13
14. APPLICATION
Elastomers are used in various consumer
products, such as footwear, sports equipment,
and household appliances. They provide
comfort, grip, and durability to these products.
Consumer products
Elastomers are the main component of tires
because of their ability to provide good traction,
durability, and resistance to wear and tear. They
are used in various types of vehicles, such as cars,
trucks, airplanes, and bicycles.
Industrial hoses and belts
14
15. ADVANTAGES OF ELASTOMERS-
Color matching
Growing market
Melt properties
Eco-friendly
Cost effective
Safe for the medical and food &
beverage industries
Advantages
Resistant
15
16. DISADVANTAGES
• Much expensive
• General inability to bear load
• Sometimes poor chemical and heat resistance
• Can be easily distorted
• Sometimes low thermal stability.
Elastomer has some disadvantages as
16
17. CONCLUSION
Elastomers are slightly cross-linked and amorphous, have extremely weak
intermolecular forces, a low Young’s modulus and a glass transition temperature below
room temperature.
They are characterized as a viscoelastic material, which means that they have both
elasticity and viscosity.
In addition, they have a high failure/yield stress.
17