Thermosets
are materials that have the property of becoming hard and
rigid when cured and are moldable when heated. Thermosets
fuse when heated and harden and become rigid when cooled.
Phenol resins and plastics were the original synthetic thermosetting
materials. Thermosets can come in many different chemical
formulae, giving them different chemical properties, and
in varying thicknesses -- both of which affect their coefficient
of expansion. Thermosets include castable polyurethane,
rubbers, epoxies, etc. Castable polyurethane is a material
manufactured many companies, such as PRC-Desoto.
Successful long term bonding of thermosets to
themselves, and to other substrates, requires careful
preparation and matching of the adhesive being used
with the differing COEs of the substrates involved
and matching other mechanical and chemical properties
for the application. BONDiTTM products
are among the few available that can be used to bond
themosetsto substrates with differing COE's for harsh
environments and long term deployment without debonding.
See also our discussion of COE's.
Our
recommendation for bonding castable polyurethane to other
substrates during the casting process is the BONDiT TM B-45,
or with an adhesion promoter like the BONDiTTM A-43
or C-6.
In circumstances requiring very high moisture resistance we recommend substituting
the BONDiTTM A-3 in place of the A-43 or C-6.
In bonding to cured parts casted using castable urethane, we recommend simply
using BONDiTTM B-45 -- no adhesion promoter is necessary.
Our
recommendations for bonding to rubbers is contained in a
separate discussion.
Our recommendation for bonding to epoxies is any of the BONDiTTMB-4X
line, depending on the required resistance properties of the use and environment
to which the bond will be subjected. Please call for specific application recommendations.
Among
the other substrates which thermosets can be bonded to using BONDiTTM products
are: UHMW, Delrin, fluoropolymers, copolymers, polyethylene,
polyolefin, polypropylene, polyurethane, silicone, rubber, thermoplastics,
urethane, other thermosets and thermoplastics, ceramics, glass,
fiberglass, wood, metals, stone, aggregate and concrete.
To see
our chart showing elongation rankings of the various BONDiTTM products clickhere. Call or email us for advice on for COE ratings
and matching BONDiTTM products
for your application at (707) 284-8808 or reltek@reltekllc.com.