BUTYL RUBBER

The primary attributes of butyl rubber are excellent impermeability/

air retention and good flex properties, resulting from low levels of

unsaturation between long polyisobutylene segments.

it also has good impermeability, weathering resistance, ozone resistance,

vibration dampening, and stability

Butyl rubber is difficult to handle during manufacturing because of its

tendency to trap air, blister, and creep.

Characteristics and flame resistance are poor.

It has poor resistance to aromatic hydrocarbons , aliphatic hydrocarbons

(e.g., kerosene, turpentine), coal, tar, and diester-based lubricants.

Cold weather properties for butyl rubber are fair.

synthetic materials tend to offer better resistance to environmental factors

such as oils, temperature, chemicals or ultraviolet light and suchlike

compared to natural rubber.

It is also resistant to deterioration; however, its comparative physical

properties are significantly less than those of natural rubber.

APPLICATIONS

Polyisobutylene added in small amounts to the lubricating oils used in

machining results in a significant reduction in the generation of oil mist

and thus reduces the operators inhalation of oil mist. When added

to crude oil it increases the oils viscoelasticity when pulled, causing the oil

to resist breakup when it is vacuumed from the surface of the water.

Polyisobutylene is often used by the explosives industry as a binding agent

in plastic explosives such as C-4. Polyisobutylene binder is used because it

makes the explosive more insensitive to premature detonation as well as

making it easier to handle and mold.

Butyl rubber is used for the bladders in sporting balls, e.g. Rugby balls,

footballs, basketballs, netballs to provide a tough, airtight inner

compartment.

Butyl rubber sealant is used for damp proofing, rubber roof repair and for

maintenance of roof membranes

Polyester fabric laminated to butyl rubber binder provides a single-sided

waterproof tape that can be used on metal, PVC, and cement joints. It is

used for repairing and waterproofing metal roofs.

Butyl Rubber v Natural Rubber

Butyl rubber is one of the most robust elastomers when subjected to

chemical warfare agents and decontamination materials. It is therefore

used to create seals in gas masks and other protective clothing.

Butyl and Bromobutyl rubber are commonly used for manufacturing

rubber stoppers used for sealing medicine vials and bottles.

Most modern chewing gum uses food-grade butyl rubber as the central

gum base, which contributes not only the gums elasticity but an

obstinate, sticky quality which has led some municipalities to propose

taxation to cover costs of its removal.

Butyl rubber and halogenated rubber are used for the inner liner that

holds the air in the tyre.

Butyl Rubber v Natural Rubber

NATURAL RUBBER

Natural rubber consists of suitable polymers of the organic compound

isoprene with minor impurities of other organic compounds plus water.

The natural rubber is harvested mainly in the form of the latex from certain

trees.

Natural rubber has better processing and physical properties than

synthetic or silicone rubber.

Natural rubber deteriorates more rapidly than synthetic rubber.

Has high molecular weight with viscoelastic properties.

Due to the presence of a double bond in each repeat unit, natural rubber

is susceptible to vulcanisation and sensitive to ozone cracking.

Vulcanised rubber will have very high tensile strength and comparatively

low elongation.

Its hardness and abrasion resistance also will be high

water repellent and resistant to alkalies and weak acids.

less buildup of heat from flexing and greater resistance to tearing when

hot.

Tensile strength, elongation and abrasion resistance is excellent over a

wide hardness range

with the exception of certain formulations of polybutadiene, it has the

highest resilience of all rubbers.

With its good tear strength, fatigue resistance and excellent compression

set it is the ideal choice for dynamic applications at low and ambient

temperatures.

Weathering resistance is good for black compounds but only fair for white

and coloured mixes.

It has poor resistance to elevated temperatures and is susceptible to

attack by ozone unless specifically compounded with anti-ozonants.

APPLICATIONS

latex products such as surgeons' gloves, condoms, balloons and other

relatively high-value products.

The mid-range which comes from the technically-specified natural rubber

materials ends up largely in tires

conveyor belts, marine products, windshield wipers and miscellaneous

rubber goods.

anti-vibration mounts, drive couplings, haul-off pads and tyres.

Butyl Rubber v Natural Rubber

Supplementary Information

BASIC PROPERTIES OF ELASTOMERS

Figure 1. an indication of the properties achievable for a range of elastomers

Figure 2. Natural rubber(left) and Butyl Rubber (Right)