"Chemistry"
Slide 2
Eugene G. Rochow
Father of Modern Silicone Chemistry
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Eugene Rochow has made some of
the most significant contributions to the study and commercialization of
silicon compounds. |
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The “Direct Process” allowed
for commercial usage over the older “Gringnard Process”. The “Direct Process
now bears Rochow’s name. |
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Chemistry of Silicones (John
Wiley) by Rochow published in 1946 is not only an extremely interesting
historical work, but still contains some very enlightening data. |
Quartz
Silicon
Hydrolysate
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Chlorosilanes |
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Si + CH3Cl ------>
Chlorosilanes |
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Mixture |
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Hydrolysate
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Hydrolysis of Rochow
Chlorosilanes |
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Rochow Process Products +
Water ---> |
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Hydrolyzate and
HCl |
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Silicone Compounds
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Performance is dictated by |
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1. Construction, |
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2. Functionalization |
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and |
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3. Derivatization |
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Silicone Compounds
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Construction relates to the
make up of the silicone backbone. |
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Functionalization relates to
the groups that are on the silicone backbone. |
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Derivatization relates to
chemistry conducted on the groups added by Functionalization. |
Silicone Compounds
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The “Construction” relates to
the polymer backbone. It is prepared by reacting various silicone precursors
to make the “silicone backbone”. The “M”, “D”, “T” are part of the
construction. |
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The “Functionalization” relates
to the functional groups that are present. They are generally a direct
consequence of Si-H groups reacted with unsaturated groups in a process
called “Hydrosilylation”. |
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“Construction”
“Functionalization” and “Derivatization ” result in the properties of the
compound. Both are rarely disclosed making proper selection of a product
difficult. |
Construction
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Polymer Backbone |
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Preparation |
Construction (Silicone
Portion)
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“M unit” is monosubstituted |
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“D unit” is disubstituted |
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Construction (Silicone
Portion)
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“T unit” is trisubstituted |
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“Q unit” is Quadsubstituted |
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Construction (Silicone
Portion)
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If organofunctional groups
other than carbon are introduced, an “*” is
added to its designation. |
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“M* unit” is monosubstituted |
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“D* unit” is disubstituted |
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with organofunctionality |
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Construction (Silicone
Portion)
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“T* unit” is trisubstituted |
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with organofunctionality |
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There is no “Q* unit” since
there is no possibility of functional groups. |
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Construction
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There are three types of
construction of silicone polymers. They are: |
Construction
Functionalization
Slide 19
Just a Few
Hydrosilylatable Olefins
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Alkoxylated allyl alcohol |
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CH2=CH-CH2-O-(EO)a-(PO)b-(EO)cH |
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Alpha olefin CH2=CH- (CH2)n
CH3 |
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Fluoro alpha olefin CH2=CH-CH2- (CF2)n
CF3 |
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Ester
CH2=CH-(CH2)8-C(O)-OCH3 |
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Combinations |
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Multifunctionals |
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Construction /
Functionalization
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The “construction” is the
molecular knitting machine that makes the silicone backbone. |
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The “Functionalization” is the
“Lego Set” of appendages that provide additional functionality. |
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“Construction” without
“Functionalization” results in silicone homopolymers like fluids. |
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“Functionalization” is not
possible without “Construction”. |
Group Opposites
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Hydrophilic (water loving) Hydrophobic (water hating) |
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Oleophilic (oil loving) Oleophobic (oil hating) |
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Siliphilic (silicone loving) Siliphobic (silicone hating) |
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Hydrophobic (water hating)
materials can be either oleophilic or siliphilic. |
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Oleophobic (oil hating) materials may be either
hydrophilic or siliphilic. |
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Siliphobic
(silicone hating) materials may be either oleophilic or hydrophilic. |
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This means that a hydrophobic
fiber can be treated with silicone or with hydrocarbon. |
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If treated with silicone, the
fiber will also be oleophobic. If treated with oil, the fiber will also be
siliphobic. |
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For application in
waterproofing fibers, selection of the proper molecule is critical. Improper
selection will result in unacceptable oil staining. |
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