RTV moisture cure systems for silicone
polymers
Alkoxy, acetoxy, or oxime
Reaction: Condensation
Reactants/functionality: SiOH/SiOR, SiOAc, or SiONºC
Catalysts: Tin salts, titanium alkoxide, moisture
Stimulus for cure: Heat or exposure to humidity |
Common applications:
Building sealants, bathtub caulk, roof coatings, elastomers, curable medical
adhesives, electronics adhesives, fabric and leather waterproofing coatings
Advantages
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RTV (room-temperature vulcanizing); cure can be accelerated by increasing
temperature and humidity
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Robust cure system
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One-part ease of use
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Relatively low cost
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Good adhesion
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Neutral cure options (alkoxy)
Disadvantages
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Shelf- and pot-life limitations related to the potential for accidental
exposure to moisture vapor.
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Acetoxy cure generates acetic acid, which is corrosive to metal and has an
unpleasant vinegar odor.
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Isopropyl alcohol or lithium-based additives found in greases and
lubricants can inhibit some moisture cure products.
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Relatively slow rate of cure.
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Only useful for relatively thin sections due to moisture requirement; not
good for highly confined applications.
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