2_Butadiene and Polybutadiene
Transcript of 2_Butadiene and Polybutadiene
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Butadiene -IntroductionButadiene is a simple conjugated diene with
the formula C4H6.
Isomers: 1,-!utadiene and 1,"-!utadiene
It is an important industrial chemical used as amonomer in the production of s#nthetic ru!!er.
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$roduction- Extractionfrom C4 Hydrocarbons$roduced as a !#product of the steam crac%ing
process used to produce eth#lene and other ole&ns.
'liphatic h#drocar!osn mi(ed with steam, heated to
)er# high temperatures *often o)er + C, producesa comple( mi(ture of unsaturated h#drocar!ons,including !utadiene.
/ight feeds, such as ethane gi)e primaril# eth#lenewhen crac%ed, !ut hea)ier feeds fa)or the formation
of hea)ier ole&ns, !utadiene, and aromatich#drocar!ons.
Butadiene is t#picall# isolated from the other four-car!on h#drocar!ons produced in steam crac%ing !#e(traction, which it is then stripped !# distillation.
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From Dehydrogenation
of n-Butane'lso can !e produced !# the catal#tic
deh#drogenation of normal !utane.
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From EthanolButadiene is also produced from ethanol.
0ot competiti)e with steam crac%ing for
producing large )olumes of !utadiene, lowercapital costs ma%e production from ethanol a)ia!le option for smaller-capacit# plants.
wo processes are in use.
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2ingle-step process, ethanol is con)erted to!utadiene, h#drogen, and water at 434C o)er an# of a )ariet# of metal o(idecatal#sts
2 CH3CH
2OH → CH
2=CH-CH=CH
2 + 2 H
2O + H
2
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two-step process, ethanol is o(idised toacetaldeh#de, which reacts with additionalethanol o)er a tantalum-promoted poroussilica catal#st at "3 C.
CH3CH
2OH + CH
3CHO → CH
2=CH-CH=CH
2 + 2 H
2O
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From ButenesB# catal#tic deh#drogenation of normal
!utenes. Howe)er this process is thought to!e no longer practiced commerciall#.
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Uses5ost !utadiene is pol#merised to produce
s#nthetic ru!!er.
2maller amounts of !utadiene are used toma%e the n#lon intermediate, adiponitrile.
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$ol#!utadieneIt is a s#nthetic ru!!er that is a pol#mer
formed from the pol#merisation process of themonomer 1,-!utadiene.
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Polymerization ofbutadiene' h#drocar!on diene molecule has two car!on-
car!on dou!le !onds*i. e. !etween two sets ofcar!on atoms. $ol#!utadiene can !e formed from
man# 1,-!utadiene monomers undergoing freeradical pol#merisation to ma%e a much longerpol#mer chain molecule.
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he trans dou!le !onds allow the pol#mer chainto sta# rather straight, allowing sections ofpol#mer chains to line up against each other and
eecti)el# form microcr#stalline regions in thematerial.
he cis dou!le !onds cause a !end in thepol#mer chain, pre)enting pol#mer chains fromlining up and forming cr#stalline regions andresulting in larger regions of amorphous pol#mer.5aterial with a su!stantial percentage of cis
dou!le !ond con&gurations will gi)es 7e(i!leelastomer *ru!!er-li%e 8ualities.
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'ssignment0atural and 2#nthetic 9u!!ers*ump 1 dan
2#nthetic 9u!!er 5anufacturing $rocess *ump " dan 6
2#nthetic 9u!!er: 'pplications and ;ses *ump dan