URETHANE is ethyl carbamate, one of a group of organic compounds sharing a common functional group with the general structure (-NH(CO)O-). Carbamates are esters of carbamic acid, NH2COOH, an unstable compound. Since carbamic acid contains a nitrogen attached to a carboxyl group, it is also an amide. Therefore, carbamate esters may have alkyl or aryl groups substituted on the nitrogen, or the amide function. Urethane or ethyl carbamate, is unsubstituted, while ethyl N–methylcarbamate has a methyl group attached to the nitrogen. Urethane should not be confused with polyurethane which is not made from carbamic acid at all. Urethane is available in many different chemical formulae (due to additives), giving it different chemical properties, and in varying thicknesses -- both of which affect its coefficient of expansion. Urethanes can generally be classified into four groups, thermoplastic urethanes, urethane rubber, urethane as a coating and urethane adhesives all of which have differing uses and physical properties.

Successful long term bonding of urethane to itself, and to other substrates, requires careful preparation and matching of the adhesive being used with the differing COEs of the substrates involved. BONDiT^TM products are among the few available that can be used to bond urethanes to substrates with differing COE's for harsh environments and long term deployment without debonding.

Our first recommended product for thermoplastic urethanes, urethane rubber and urethane coatings is to first apply an adhesion promoter or primer such as BONDiT^TM A-43 or C-6, followed by one of the BONDiT^TM B-4X series adhesives.

Our recommendation would change if unusually high chemical resistance is necessary in which case we recommend our BONDiT^TM A-3, in place of the A-43 above.

Our other recommended product for urethane adhesives is simply using any of the BONDiT^TM B-4X line products, unless high moisture resistance is required -- in which case we recommend using an adhesive promoter BONDiT^TM A-3 first.

Among the other substrates which urethanes can be bonded to using BONDiT^TM products are: UHMW, Delrin, fluoropolymers, polyethylene, polyolefin, polypropylene, polyurethane, other urethanes, rubber, silicone, thermoplastics, thermoset, ceramics, glass, fiberglass, wood, metals, stone, aggregate and concrete.

To see our chart showing elongation rankings of the various BONDiT^TM products click here. Call or email us for advice on for COE ratings and matching BONDiT^TM products for your application at (707) 284-8808 or reltek@reltekllc.com