styrene butadiene rubber

Table Of Contents

I. Introduction. 1

II. The Molecular Formula. 2

III. Production. 3

IV. Types Of SBR. 4

V. Buna S. 4

VI. Properties Of SBR. 5

VII.Appilications. 6

VIII.Flow Sheet. 7

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I.Introduction:• Styrene-butadiene or styrene-butadiene rubber (SBR) describe families of synthetic rubbers derived from styrene and butadiene.• These materials have good abrasion resistance and good aging stability when protected by additives.• About 50% of car tires are made from types of SBR.• The styrene/butadiene ratio influences the properties of the polymer: with high styrene content, the rubbers are harder and less rubbery.

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II.The Molecular Formula :

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III.Production:From ethanol

In other parts of the world, including South America, Eastern Europe, China, and India, butadiene was also produced from ethanol. While not competitive with steam cracking for producing large volumes of butadiene, lower capital costs make production from ethanol a viable option for smaller-capacity plants. Two processes were in use.

In the single-step process developed by Sergei Lebedev, ethanol is converted to butadiene, hydrogen, and water at 400–450 °C over any of a variety of metal oxide catalysts.

2 CH3CH2OH → CH2=CH-CH=CH2 + 2 H2O + H2

IV.Types of SBR:SBR is derived from two monomers, styrene and butadiene. The mixture of these two monomers are polymerized by two basically different processes: from solution (S-SBR) or as an emulsion (E-SBR).

1. Emulsion polymerization:E-SBR produced by emulsion polymerization is initiated

by free radicals.

2. Solution polymerizationSolution-SBR is produced by an anionic polymerization

process.

V.Buna S:The material was initially marketed with the brand name Buna S. Its

name derives Bu for butadiene and Na for sodium (natrium in several languages including Latin, German and Dutch), and S for styrene.

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VI.The Properties Of SBR:

Property E-SBR

Tensile Strength 19

Elongation at tear 635

Glass TransitionTemperature

-50

Property S-SBR

Tensile Strength 18

Elongation at tear 565

Glass Transition Temperature

-65

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VII.Applications:1. The elastomer is used widely in pneumatic tires, shoe heels and soles, gaskets and even chewing gum. 2. It is a commodity material which competes with natural rubber. 3. Latex (emulsion) SBR is extensively used in coated papers, being one of the most cost-effective resins to bind pigmented coatings. 4. It is also used in building applications, as a sealing and binding agent behind renders as an alternative to PVA, but is more expensive.

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VIII.Flow Sheet: