Difference between revisions of "Silicone sealant"

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== Description ==
 
== Description ==
  
A water-resistant, flexible adhesive (caulk or sealant). Silicones contain easily hydrolyzable end groups, such as acetates, that are designed to crosslink when exposed to water vapor in the air. Since they crosslink at room temperature (within 24 hours), they are often call RTV silicones (Room Temperature Vulcanization). Some types of one-part curing include:
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A water-resistant, flexible adhesive (caulk or sealant). Silicones contain easily hydrolyzable end groups, such as acetates, that are designed to crosslink when exposed to water vapor in the air. Since they crosslink at room temperature (within 24 hours), they are often call RTV silicones (Room Temperature Vulcanization). Some types of one-part silicone curing systems include: acetic-cure cure; alkoxy neutral-cure and oxime neutral-cure.  A comparison for some of their properties are listed below.
 
 
* Acetoxy cure silicones may release [[acetic%20acid|acetic acid]] during cure
 
* Alkoxy Neutral cure silicones may release [[methanol|methanol]] or other alcohols during cure.   
 
* Other Neutral cure silicones may release methyl ethyl ketoxime or [[acetone]] during cure.
 
 
 
 
Other types of silicone systems use a catalyst for cure.  These are called 2-part systems.
 
Other types of silicone systems use a catalyst for cure.  These are called 2-part systems.
  
 
{| class="wikitable"  
 
{| class="wikitable"  
 
|-
 
|-
! Acetic-cure siliconesAlkoxy neutral-cure silicones Oxime neutral-cure silicones Maximum temperature +200°C/+392°F (+275°C/+527°F for high-temperature SKUs) +180°C (+356°F)+220°C (+428°F) OdorStrong (vinegar)Slight Slight Unsuitable substrates Corrosion-sensitive metals (copper
+
! <br />
! crude steel
+
! <br />Acetic-cure   silicones
! crude aluminum
+
! <br />Alkoxy  neutral-cure silicones
! iron
+
! <br />Oxime neutral-cure   silicones
! zinc
+
|-
! lead
+
| <br />Maximum   temperature
! etc.) None Polycarbonate and PMMA (stress crackingcopper (discoloration) Smoothing agentSoapy water/Silicone liquidsSilicone liquidsSilicone liquids
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| <br />+200°C/+392°F
 +
| <br />+180°C (+356°F)
 +
| <br />+220°C (+428°F)
 +
|-
 +
| <br />Odor
 +
| <br />Strong  (VINEGAR)
 +
| <br />Slight
 +
| <br />Slight
 +
|-
 +
| <br />Unsuitable   substrates
 +
| <br /> Corrosion-sensitive METALS (Copper, crude   steel, crude aluminum, iron, zinc, lead, etc)
 +
| <br />None
 +
| <br />Polycarbonate   and PMMA (stress cracking and copper discoloration)
 +
|-
 +
| <br />Smoothing   agent
 +
| <br />Soapy  water/Silicone liquids
 +
| <br />Silicone  liquids
 +
| <br /> Silicone liquids
 +
|-
 +
| <br />Released volatiles
 +
| <br />[[acetic%20acid|acetic acid]]
 +
| <br />[[methanol|methanol]], other alcohols
 +
| <br />methyl ethyl ketoxime, [[acetone]]
 
|}
 
|}
 +
 
== Synonyms and Related Terms ==
 
== Synonyms and Related Terms ==
  

Revision as of 13:16, 12 September 2023

Description

A water-resistant, flexible adhesive (caulk or sealant). Silicones contain easily hydrolyzable end groups, such as acetates, that are designed to crosslink when exposed to water vapor in the air. Since they crosslink at room temperature (within 24 hours), they are often call RTV silicones (Room Temperature Vulcanization). Some types of one-part silicone curing systems include: acetic-cure cure; alkoxy neutral-cure and oxime neutral-cure. A comparison for some of their properties are listed below. Other types of silicone systems use a catalyst for cure. These are called 2-part systems.



Acetic-cure silicones

Alkoxy neutral-cure silicones

Oxime neutral-cure silicones

Maximum temperature

+200°C/+392°F

+180°C (+356°F)

+220°C (+428°F)

Odor

Strong (VINEGAR)

Slight

Slight

Unsuitable substrates

Corrosion-sensitive METALS (Copper, crude steel, crude aluminum, iron, zinc, lead, etc)

None

Polycarbonate and PMMA (stress cracking and copper discoloration)

Smoothing agent

Soapy water/Silicone liquids

Silicone liquids

Silicone liquids

Released volatiles

Acetic acid

Methanol, other alcohols

methyl ethyl ketoxime, Acetone

Synonyms and Related Terms

silicone caulk; silicone mastic (Br.); adhesivo de silicona (Esp.); colle silicone (Fr.); colla siliconica (It.); adesivo de silicone (Port.)

Resources and Citations

  • Irving Skeist, Handbook of Adhesives, Van Nostrand Reinhold Company, New York, 1977
  • Silicone Technologies: Silicone cure systems

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