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Catalyst to Reduce Cure Temperature in Bonding Wood with MDI

I have a wood chemistry course that indicates that methylene diphenylisocyanate (MDI) is used as a common resin and/or glue in bonding wood fibers together in composite type substrates. The cure temperature is given as approximately 425 degrees F.

I have a test question that asks us to hypothesize about a chemical additive to the MDI resin/glue that might either speed its cure time reaction or cause the cure to be at a lower temperature....say 375 degrees F.

Solution Preview

Please see the attached file.

The following is an excerpt from http://en.wikipedia.org/wiki/Polyurethane and is with reference to the reaction between polyols and MDI (or similar diisocyanates).
The polymerization reaction is catalyzed by tertiary amines, such as dimethylcyclohexylamine, and organometallic salts, such as dibutyltindilaurate. Furthermore, catalysts can be chosen based on whether they favor the urethane (gel) reaction, such as diazobicyclooctane, or the urea (blow) reaction, such as bis-dimethylaminoethylether, or specifically drive the isocyanate trimerization reaction, such as potassium octoate.

It is reasonable to suppose that catalysis with tertiary amines will produce similar results in the process posed in your question. Speeding up the polymerization process should facilitate a lower cure temperature.

The ...

Solution Summary

The solution shows examples of additives that accelerate bonding of wood with MDI.

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