The document discusses isobutylene-isoprene rubber (IIR) and its synthesized variants, including butyl rubber and halo-butyl rubber, highlighting their production methods, properties, and various applications. It details the chemical processes for vulcanization and the influence of additives, including ground tire rubber (GTR), on the mechanical properties of butyl rubber. Furthermore, it explores the extensive use of butyl rubber in consumer and industrial products due to its low permeability, excellent aging resistance, and chemical compatibility.

1. JAYA VERMA
PA-04
TY.BTECH POLYMER
ELECTIVE-I: ELASTOMER TECHNOLOGY
TUTORIAL PRESENTATION

2. Structure of Isobutylene isoprene rubber (IIR)
Butyl rubber (IIR), also called isobutylene-isoprene rubber.
It is a synthetic rubber.
It is a co polymer of isobutylene with isoprene.
Isoprene unit: Double bond that provides a site for crosslinking during
vulcanisation and located randomly in the polymer chain.

3.  Produced by cationic copolymerisation between 98% isobutylene and 2%
isoprene.
 Initiator: Friedel Craft acids (e.g. AlCl3).
 Medium: Methyl chloride (reaction diluent) & boiling liquid ethylene.
 Temperature: Controlled at low temperature -90˚C to -100˚C.
TYPICAL METHOD
Butyl rubber
The alkyl chlorides can be ranked in the following order with respect to a
decrease in the carbocation stability: benzyl chloride > tert-butyl chloride >
chlorinated isobutylene dimers > chlorinated propylene trimers.

4.  Mixture of a major amount of diethyl aluminium chloride & a minor
amount of ethyl aluminium dichloride (activated by minute amounts
of water/ methyl alumino {MAO}).
 Modified initiators: Higher molecular weights, higher degrees of
conversion and higher isoprene contents in butyl rubber.
 Medium: Hexane
 Temperature: -60˚C
 Activation by MAO allow higher polymerisation temperature which
does not require much heat removal from reaction mixture.
ALTERNATIVE METHOD

5.  Halogenated butyl rubber (halo-butyl) was developed, in its chlorinated (chloro-
butyl) and brominated (bromo-butyl) variants, providing significantly higher
curing rates and allowing co-vulcanization with other rubbers such as natural
rubber and styrene-butadiene rubber.
 The introduction of bromine or chlorine improves the resistance to ozone,
weathering, chemicals, and heat. This, however, comes at the expense of electrical
insulation and moisture resistance.
 Halo-butyl is today the most important material for the inner linings of tubeless
tires.
Because of its excellent weather and ozone
resistance, and improved chemical
resistance, chloro-butyl is an excellent
choice for rubber articles needing good
resistance to chemicals, weathering and
ozone such as tank linings, special purpose
conveyor belts and protective clothing. It is
also a good choice for tire inner liners, seals
and membranes. Furthermore, chlorinated
butyl is often the material of choice for
pharmaceutical closures due to its
cleanliness and good resealing properties.
Bromo-butyl together with chloro-butyl
rubber provide excellent inflation pressure
retention. However, the brominated sites are
more reactive, providing faster cure and better
adhesion to unsaturated rubber types. They are
the most widely used rubbers for inner tubes of
bicycles, trucks as well as industrial and
agricultural tires. Bromo-butyl rubbers are also
used for hoses, seals, membranes, tank linings,
special purpose conveyor belts, engine mounts,
protective clothing and for consumer products
such as ball bladders for sporting goods..

6.  CHLORO-BUTYL
Chloro-butyl (CIIR) is a copolymer of chlorinated
isobutylene and small amounts of isoprene which provides
unsaturated sites for vulcanization. This elastomer has
many of the attributes of butyl rubber, including low gas
and moisture permeability, good vibration damping, low
glass transition temperature, excellent resistance to ageing
and weathering. Compared to butyl rubber, the chlorinated
sites are more reactive, providing faster cure with lower
amount of curatives and better adhesion to unsaturated
rubbers and metals.
 BROMO-BUTYL
Bromo-butyl (BIIR) is a copolymer of isobutylene and small
amounts of brominated isoprene which provides
unsaturated sites for vulcanization. This elastomer has many
of the attributes of butyl rubber, including low gas and
moisture permeability, good vibration damping, low glass
transition temperature, excellent resistance to ageing and
weathering, and wide vulcanization versatility. The
introduction of bromine increases adhesion to other rubbers
and metals and provides much higher curing rates (i.e. lower
amount of curative are required). Furthermore, brominated
butyl can be co-vulcanized with general purpose high-
unsaturation elastomers, such as natural rubber,
polybutadiene, and styrene-butadiene rubber, while
maintaining the mostly saturated backbone structure.
MANUFACTURERS & DISTRIBUTORS
EXXON MOBILE, ARLANXEO
BRAND NAMES
EXXON CHLORO BUTYL RUBBER,
CHLORINATED X_BUTYL
MANUFACTURERS &
DISTRIBUTORS
EXXON MOBILE, ARLANXEO,
SINOPEC
BRAND NAMES
EXXON BROMO BUTYL RUBBER,
BROMINATED X_BUTYL

7.  Low permeability to air, gases and moisture
 Vibration damping
o Converting the mechanical vibrational energy of solids into heat
energy
 Low glass transition temperature
 Low modulus of elastomer
o Elastomer: able to stretch a long distance and regain the shape.
 Low compression set
o Compression set: percentage deflection from original shape of rubber a
item having been subjected to a constant compressive load, then
released.
 Resistance to aging and weathering from atmospheric exposure
 Wide vulcanization versatility
o Vulcanization: Chemical process for converting rubber into a
compound material (polymer) with the addition of sulphur.

8.  Fast cure rates
o Cure rates: Toughening or hardening of a polymer material by
cross linking of polymer chains.
 Processing safety: No nitrosamines or nitrosamines precursors
o Nitrosamines: Carcinogenic and can cause cancer.
 High extensibility
o Broad range of durometer and tensile strength properties
o Low filler content for specific gravity, cost effective
compounding
 Best sealant of all the known rubbers
o Sealant rubber – Type of product seals and protects different
materials using rubber – based substances.
o Caulk – To make watertight or airtight by filling or sealing
 Blood compatible
o Allows this substance to be used in biomedical applications.
Contd.

9.  What is curing of rubber?
Ans: Curing, also known as vulcanization, causes the long polymer chains that
rubber is composed of to become crosslinked. This prevents the chains from
moving independently, allowing the material to stretch under stress and then
return to its original shape when the stress is released.
 Why to cure the butyl rubber?
Ans: Vulcanized or cured butyl rubber is a strong, non-plastic material; it has
an elastic limit, as well as the ability to return substantially to its original
length after being stretched as much as several hundred per cent.
 How to cure the butyl rubber?
Ans: Butyl rubber is typically cross-linked or vulcanized by one of three basic
methods.
(1) accelerated sulphur vulcanization,
(2) cross-linking with dioxime and related dinitroso compounds, and
(3) a phenol-formaldehyde (resol) resin cure.

10.  Butyl rubber is cross-linked or vulcanized by phenol-formaldehyde (resol)
resin cure.
 The curing agents generally used include phenols and phenol-formaldehyde
resins produced by condensation of a phenol with formaldehyde in the
presence of base.
 Typical agents include 2,6-dihydroxymethyl-4-alkyl phenols and their
polycyclic condensation polymers.
 Curing occurs through the reaction of the methylol groups of the phenols or
resin with the uncured rubber to form cross-linked structures.
 The resin-cured butyl rubbers with improved properties are obtained by
curing the butyl rubbers with low amounts of phenol-formaldehyde resins
with low levels of ether bridging. Such improved properties may include
improved high-temperature ageing characteristics, faster cure rates, and better
stress/strain properties.
 Base-catalysed phenol-formaldehyde resins are made by condensing a phenol
with formaldehyde in the presence of base.

11. • The GTR content variation, within the range of 10–90 phr(parts per hundred
rubbers), was studied with respect to the vulcanization process, static
mechanical properties (tensile strength, elongation-at-break, hardness and
resilience), dynamic mechanical properties and the morphology of the obtained
vulcanizates.
• Rubber compounds based on butyl rubber filled with were obtained using a
laboratory mill.
• The obtained rubber compounds were vulcanized according to the estimated
optimal time at 160 ˚C under a pressure of 4.9 MPa.
Results and discussion obtained from the experiment:
1. Swelling Degree: Swelling degree increased with GTR content in butyl
vulcanizates, which was due to low cross-linking of butyl rubber matrix and
lowering of cross-linking density of GTR arising from partial de-vulcanization of
GTR.
2. Cure characteristics: It was observed that there is an increase in minimum torque
and lowered optimal time of vulcanization with the increasing GTR content. GTR
aggregates with a complex structure, give rise to the formation of free spaces in
the rubber matrix which results in increased viscosity of the blends.

12. 3. Mechanical properties: Higher values in tensile strength and elongation-at-break have been
caused by the carbon black migration from GTR into the butyl rubber matrix.
4. Dynamic mechanical analysis: Storage modulus is decreased with increasing GTR content
as a result of the de-vulcanization of GTR structure and slightly cross-linking of butyl
rubber matrix, which results in vulcanizates with lower stiffness.
5. Morphology:
Effect of GTR content on hardness and
resilience of the butyl rubber vulcanizate
The influence of butyl rubber content on
residue after determining the degree of
swelling and the sol fraction content in
ground tire rubber.
Tested contents of butyl rubber:
a. 10, b. 20, c. 30, d. 40 and e. 50 wt%
Conclusion:
This phenomenon visibly increased elongation-at-break values of the obtained vulcanizates. The
microstructure analysis of samples performed after tensile tests showed that there was a strong
interaction between the butyl rubber matrix and GTR. The obtained results demonstrated that
GTR can be successfully used as non-expensive filler in butyl rubber-based compounds.

13. 1. Processing: Butyl undergoes little breakdown during milling. Butyl is an ideal
material for Banbury mixing since no premastication in necessary before the
Banbury operation can be carried out. The condition referred to above which
makes for rather difficult handling during the early stages of open mill mixing is
not a factor in this operation.
2. Physical properties: An increase in the unsaturation from 0.8 to 2.0 percent of
butyl rubber changed the time of cure at which optimum tensile properties were
obtained from over 60 minutes to 15minutes or less.
3. Pigment loading: Carbon blacks are by far the best pigments for use in butyl
rubber and the properties imparted by any one black depend upon particle size
and surface condition.
4. Elasticators: The rebound characteristics of butyl can be improved considerably
by the use of small amount of Elasticators.
5. Aging: Butyl possesses excellent aging characteristics since all, or nearly all, of
its small amount of unsaturation is taken up during vulcanization, leaving few
points for oxygen to attack. Butyl is exceptionally resistant to the action of
ozone.

14. Tires
&
Lubes
Adhesive,
Sealants,
Stoppers
COMPONENT DETAILS
Tires
Provide excellent inflation pressure retention for
bicycle, truck, agricultural, industrial and speciality
tires
Automotive
Butyl rubbers’ barrier properties, high damping,
resistance to ozone and heat aging make them ideal
for automotive vibration control, hoses and gaskets
Industrial
Use butyl rubbers to improve formulations for
conveyor belts, tank linings and condenser packaging
Construction
Improve weather ability of asphalt, contact cement
and sealant tapes
Adhesives
Tailor adhesive properties in valve cement, tapes and
flooring adhesives.
Consumer
Products
For ball bladders for sporting goods and electrical
appliance condenser packaging
Sealant
properties
Butyl rubber caulk is known as the strongest bond,
and is usually used to fill in cracks in bricks, concrete
and metal
Blood
compatible
Artificial joint materials and blood collection tubes.

15.  Rubber roof sealants and repair
 Shock mounts
 Diaphragms
 Tubeless tire liners
 Bottle stoppers
 Pharmaceutical packaging and
bottles
 Sealants and adhesives
 Butyl O-rings
 Pond and tank liners and seals
 Industrial liners
 Construction and mechanical
systems
 Speaker surrounds
 Industrial hoses and connections

16. POLYCOTE
Poloflex - Butyl Rubber
Waterproofing Roof

17. Butyl Rubber Molding
Processes
1. Transfer Molding
2. Injection Molding
3. Compression Molding

18. • Due to its low gas and vapor permeability, butyl rubber is an important material in the
manufacturing of tubeless tires, inner tubes, sports-ball bladders, glove-box gloves, etc.
Owing to its low permeability, it is used in making gas masks. Though not as soft and
compliant as silicone rubber, butyl rubber is flexible enough that it can achieve a good face
seal.
• As a waterproofing material, it is applied as a liner in tanks and ponds.
• It is used as a patching material for membrane roofs and as a sealant for insulated windows.
Combined with other chemicals, polyisobutylene makes oil and fuel additives and demisting
agents for machining lubricants.
• As a vibration dampener, butyl rubber is used for shock mounts, suspension bushings, and
car- and truck-body mounts. Speaker cone edges are often made from butyl rubber today
where once they were commonly made of foam. Stoppers for labware and medical equipment
are manufactured from the material.
• Compared with natural rubber, butyl rubber is costlier due to more complex processing
requirements. Some anecdotal discussion exists regarding natural vs. butyl rubber
motorcycle tire tubes, as the natural rubber is said to have better puncture resistance and tear
strength but butyl rubber tubes can go longer between airings.
• Butyl rubber, in its food-grade form, is used to make chewing gum. It has all but replaced
the gum of the Chicle tree except in a few specialty, natural products. There have been some
efforts to collect used chewing gum and recycle it into new products. Improper disposal of
chewing gum is a chronic urban blight.

19. Gum under your shoe is normally
annoying - but these soles are
made from recycled gum
The bright bins are themselves
made of used chewing gum
The gum mixture is heated to a high
temperature before being expelled in
an injection machine

20. • Most modern chewing gum uses
food-grade butyl rubber as the
central gum base, which contributes
not only the gum's elasticity but also
gives it a stubborn, sticky quality
which has led some municipalities
to propose taxation to cover costs of
its removal.
• Recycled chewing gum has also been
used as a source of recovered
polyisobutylene. Amongst other
products, this base rubber has been
manufactured into coffee cups and
'Gumdrop' gum-collecting bins.
• When filled, the collecting bins and
their contents are shredded together
and recycled again.

21. REASONS TO USE BUTYL CHEMICAL
PROTECTION GLOVES
1. Cost Savings Using Butyl Gloves
2. Offer Superior Chemical Protection
3. Reduce Waste
4. Quality Chemical Protection
Products
5. Different Thicknesses and Styles
Available

22. • Butyl rubber is the only known elastomer that is impermeable to gases.
• The material is flexible, with good room temperature damping characteristics.
• The material is biocompatible, resists many acidic and alkaline chemicals, ozone, heat,
and weathering, and has good aging properties.
• It has good electrical insulating properties.
• Butyl rubber is usable between -50 and 250°F but its damping characteristics diminish at
higher temperatures.
• It remains flexible at lower temperatures.
• Compression set: fair
• Flex cracking resistance: good to excellent
• Abrasion resistance: good to excellent
• Tear resistance: good
• Impact resistance: good
• Weather resistance: excellent
• Sunlight resistance: excellent
• Ozone resistance: excellent
• Oxidation resistance: excellent
• Water resistance: very good
• Steam resistance: excellent

23. • Butyl rubber is difficult to handle during manufacturing because of its
tendency to trap air, blister, and creep.
• Characteristics and flame resistance are poor. Butyl is not
recommended for use with petroleum oils, fluids, or solvents. It resists
attack by phosphate ester hydraulic fluids and ketones but does not do
well in the presence of mineral or petroleum-based fluids,
hydrocarbons, or flame.
• It has poor resistance to aromatic hydrocarbons , aliphatic hydrocarbons
(e.g., kerosene, turpentine), coal, tar, and di ester-based lubricants.
Cold weather properties for butyl rubber are fair.
• Rebound rating: poor
• Flame resistance: poor

24. National Manufacturers:
Prime white Butyl RubberAnanta Polyrubb Pvt. Ltd.
Connaught Place, Delhi
Butyl Rubber Sheet, Packaging Type: Roll M.V.Rubber
Ballabhgarh, Faridabad
Black Butyl Rubber SheetsVishal Rubber Technologies Pvt. Ltd.
Pimpri - Chinchwad, Pune
Butyl Crumb Rubber Vsj Granurubr Private Limited
Kharghar, New Delhi
International Manufacturers:
ExxonMobil Shareholder Services at 5959
Las Colinas Boulevard, Irving, Texas
LANXESS Büro Berlin
HB fuller Willow Lake Boulevard
National an International Trade Names:
KALAR® Cross-Linked Butyl Rubber
ISOLENE® Liquid Synthetic Rubber
KALENE® Liquid Butyl Rubber

25. • Curing characteristics, mechanical properties and morphology of Butyl
rubber filled with Ground tire rubber (GTR) By: Krzysztof Formela • Jozef T.
Haponiuk
• MECHANICAL PROPERTIES OF RUBBER Ronald J. Schaefer
• Thomasnet.com/articles/plastics-rubber/all-about-butyl-rubber
• Blog.oureducation.in/butyl-rubber-its-properties-and-uses
• Adroitmarketresearch.com/blogs/essential-methods-and-uses-of-butyl-
rubber
• Blog.oureducation.in/preparation-of-butyl-rubber
• Bostik-industrial.com/butyl-rubber-benefits-and-use-in-adhesive-
manufacturing/
• World Hacks: A surprising new after life for chewing gum By Dougal Shaw
World Hacks, BBC News
• BUTYL RUBBER COMPOUNDING By: P
. Haworth and F. P
. Baldwin
• Synthesis of Butyl Rubber by Cationic Polymerization in Methyl Chloride in
the Presence of Alkyl Chlorides O. V. Sofronova, E. A. Markina, S. M.
Chelnokova, and A. G. Sakhabutdinov
• MDsassociates.com/why-use-butyl-gloves
• Curing of butyl rubber with a phenolic resin William Sarnia Hopkins, and
Carl Walter von Hellens,