道康宁有机硅基础培训教程

Commercial Products
Hydrolyzates:
(Linear + Cyclics)
H2O ChloroSilanes
Me(n)SiCl(4-n)
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From sand to Silicones: 1
Linear + acid or base =>HOSiMe2-O-[Me2Si-O]y-SiMe2OH
catalyst
Silicone Polymer
+ H2O Water
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Polydimethylsiloxane (the simplest silicone)
% >50 10 - 30 <10 <5
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From sand to Silicones: 3
• Hydrolysis of Chlorosilanes :
Me2 Si Cl2 + H2O => HO(Me2 Si O)nH (linears) , n = 20-50
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How can Silicone Molecular be Changed ?
Mwt • Gum
• Viscous Fluid
• Non-Volatile
Viscous Fluid Fluid
• Volatile Fluid
• Dimethyl
• Polyether
• Cyclo • Linear •X-L
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Organofunctional Silicones
• Can replace some of the methyl groups with
alternative organic groups Me Me
Me3SiO(SiO)x(SiO)ySiMe3 Me R
• These organosilicones have additional interesting
n = 1300
50,000 cps
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ORGANOFUNCTIONAL SILICONES
Methyl groups are replaced with alternative organic groups
Ring Polymer (Cyclomethicone) Liquid,
solid
H3C
CH3
H3C
O Si
Si CH3
O (D4) O
H3C Si O Si CH3
CH3
CH3
Linear Polymer (Dimethicone) Liquid, gum
CH3
CH3
CH3
CH3 Si
CH3
Si
- Silicon The pure element Si, 28% of earth’s crust - Silica Sand , naturally occurring SiO2 - Silicate Si & O and other metals - Silicone A polymer
- Silicone exist as: linear or branched fluids, cyclics, gums, resins,
Me Me Me3-Si-O(Si-O)x(Si-O)ySi-Me3
RR
These organosilicones provide additional properties in applications compared to PDMS.
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Silicone Physico-Chemical properties
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What Kind of Materials are
Silicones?
POLYDIMETHYLSILOXANE • Silicones typically have a back
OOO Phenyl Siloxane
CroHssiglCBihnBorkamrRnioncpIaghaditenibrgility
Linear PDMS
Substantivity
A
A
OCragpaanbicility
Polarity
Silsesquioxane &
Silicates
Trimethylsilyl Amodimethicone
elastomers - There are 1000’s of different products, for 1000’s of different applications
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Applications for Silicones
• Amino
• Alkyl
• Resinous
Molecular Structure
Organo Functionality
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Silicone Chemistry
Different Molecular Structures / Physical Forms
Production
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Making Silicones : Overview
Polymerization Compounding Emulsification etc.
Separation
Cu MeCl
Medical Products Paints & Coatings Personal, Household & Automotive Care Pharmaceuticals Plastics Pressure-Sensitive Adhesives
Industrial Maintenance
Textiles & Leather
The two starting materials for our processes are silicon metal and methyl chloride
• Reduction of sand into silicon metal :
SiO2 + 2 C => Si + 2 CO
Sand (silica) Carbon Silicon Carbon monoxide
Branching
A
A
A
A
Amodimethicone
Alkyl Alkyl
Alkyl Methyl Siloxanes
PE PE Dimethicone
Copolyol
Emulsifiers
PE Alkyl PE
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Silicone Chemistry
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CONTENT
CHEMISTRY OF SILICONES. SILICONE PHYSICO-CHEMICAL PROPERTIES NOMENCLATURE
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Repeat Unit
R | -[Si - O]n| R
Polydimethylsiloxane
R = - CH3 (Me) or Organic function n = number of repeat units
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bone, which is inorganic like
CH3 CH3 CH3
glass
• The side groups are organic: in
most case methyl
CH3 - Si - O - (Si - O)n - Si - CH3 • The degree of polymerization
Dow Corning’s products and specialty materials are used by customers in virtually every major industry.
Aerospace Automotive Chemicals/ Petrochemicals Construction Consumer Products Electrical/Electronics Food Processing
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The Chemistry of silicones
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