Treatment of Polyetherification

In spite of the great importance of polyaddition (polyetherification ) of epoxy groups in many formulations, a rigorous branching theory is still to be developed. Polyetherification is often released by a primary reaction of epoxide with amines, carboxyl groups, dicyandiamide, or is initiated by BF3-amine complexes, imidazoles, etc. The polyetherification reaction is to be regarded as an initiated reaction and the initiator is either added at the beginning of the reaction of formed in the first reaction 

1 Polyetheriflcation means formation of an ether bond or sequence of ether bonds by (poly)addition of epoxy groups which is released by proton donors (like the OH group formed in the amine-epoxy addition), ionic catalysts or other initiators 

However, the actual mechanism of initiation and propagation may not be simple 

Two theoretical approaches are mentioned in Section 4.1 (Refs. but the first one is based on incorrect statistical treatment. A comparison with experiments is not available, so that the seriousness of deviations cannot be estimated. Also, a cascade theory has been developed to cover polyetherification released by the reaction of diepoxides with dicarboxylic acids but an analysis of experimental data is also lacking. An extensive pregel study of polymerization of diepoxides released by diphenols is analyzed by W. Burchard in another chapter of this volume 

It has been shown in Section 3.3 that the initiated polyetherification should be described by the kinetic theory and that a simplification is possible, if groups of independent reactivity in polyfunctional monomers participate in the curing reaction. The results of the treatment of an ideal postetherification following the epoxyamine addition are summarized below. 

---