Transcript Kein Folientitel - uni

Silicones –
Diverse properties and applications
General properties
 Adjusted by viscosity
 Properties unaffected by
changes in temperature
 Biological tolerance
 High stability to weathering
Contradictory properties
 Transparency/impermeability to light
 Electrically insulating/conducting
 Resistance to high/low temperatures
 Adhesive/nonstick properties
 Hydrophobic/hydrophilic
 Antifoams/foam stabilizers
Other applications
 Fire protection
 Shock absorbers
 Restoration/dental prosthetics
Silicones –
Biological tolerance
Si-O and Si-C bonds in silicone polymers
Physiologically inert
Medical...
(Insulin pump,
catheters...)
Pharmacological...
(Tablets/capsule coating,
toothpastes)
Cosmetics...
(Creams, lipsticks...)
Silicones –
Resistant to weathering
Silicone polymers: resistant to weathering, ozone and UV radiation;
Stability of the SiC and SiO bonds and water repellency of silicones
Highly durable facade protection
Durable, scratch and UV
resistant automotive finishes
Silicones –
Colored or colorless
O
O
O
Si
R
Colorless
• Refractive index determined by R
(Me, Ph,....)
Si
R
R
R
Pigmented
• Almost any color
• Control over properties
(Elastic, ceramifying,
corrosion protection)
Silicones –
Adhesion promoters
H2N
Adhesion to organic surfaces
(polymers)
• Organic functionality
O
(NH2, C(R)=CH2,
)
Synthetic resin
NH2
NH
(CH2)3
Adhesion to inorganic
surfaces (glass, metal)
• Si-O-M bonds
• SiOH HO-M bridges
HN
O
Si
(CH2)3
O
O
O
O O Si
O
Si
Me Si HO Me Si
Me
HO
OH
OH
M
O
O
M
Silicone
Substrate
O
O
O OH O
M
M
Si
O
M
Me
Silicones –
Structural glazing
Extremely powerful, flexible combinations of
metal and glass make innovative structures
possible
Silicone release agents
Label paper
Little interaction due to nonpolar “jacket”
Adhesive
H3C H3C H3C
CH3
CH3 CH3 CH3
CH3
O
O
Si
Si
Si
Si
O Si
Si O
O
O
O Si
Si
CH
H3C
H3C CH3
CH3 3
CH3H3C CH3
Silicone release agent
Substrate paper