Name: Tom K.
Status: Other
Age: 40s
Location: N/A
Country: N/A
Date: 2001
Question:
I have heard that using a chlorine and water as a
washdown to sanitize stainless machines attacks the neoprene gasket used
to seal an electrical enclosure access door. Neoprene is Chloroprene
Polymer.What happens when bleach is mixed with this type of rubber
(elastomer)? I suspect that both of these are made from a derivative of
chlorine (indicated by the names) and they may mix or melt together. Am I
on the right track? I am investigating this for an engineering solution.
I may have to change the material on this gasket to a silicone or a
fluoro silicone.
Replies:
Neoprene, natural rubber, and styrene-butadiene elastomers contain
carbon-carbon double bonds as an essential part of their polymer chains.
These bonds are susceptible to oxidative damage from species such as ozone
and chlorine.
I am not sure of the exact chemical structure of silicone or fluoropolymer
elastomers. In general, fluropolymers have excellent resistance to
oxidants. The information I can locate indicates that elastomeric
fluoropolymers (Viton, Kalrez), and silicone elastomers have good resistance
to ozone, so they ought to withstand bleach also.
Richard E. Barrans Jr., Ph.D.
Assistant Director
PG Research Foundation, Darien, Illinois
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