The estimation of catalytic parameters of metal acetylacetonates in isocyanate polymerization reactions

Abstract

The polyaddition process involving a hydroxy‐terminated linear polyester and an organic diisocyanate in the presence of a series of metal acetylacetonates has been investigated. The method involved kinetic analysis of plasticity build‐up in a Brabender Plastograph. Catalytic orders and relative catalytic constants (kc/k0) were determined for Mn(Aa)3, VO(Aa)2, V(Aa)3, Fe(Aa)3, Cu(Aa)2, Co(Aa)3, and Cr(Aa)3; the constants decrease in that order. Catalytic orders are unity for all complexes save manganese, which is 1.75. No correlation between dissociation potential and catalytic coefficient has been found, and it is believed that catalysis may be associated with the paramagnetic properties of the metal.

Physico-chemical characterization of mixed-ligand complexes of Mn(III) based on the acetylacetonate and maleic acid and its hydroxylamine derivative

“…The interest in this class of compounds as catalyst started in 1973, when the first compounds of this type were synthesized and studied (4).…”

A stepwise kinetic approach to quantify rate coefficients for reactant-, auto- and non-catalyzed urethanization of phenyl isocyanate and 1-butanol

“…However, the latter compounds are not preferred because of their toxicity. 2,9,17,34 Base catalyzed PU formation can take place by activating the alcohol (an example of alcohol catalysis; Scheme 4a), whereas an example of an acid catalyst for isocyanate catalysis is given in Scheme 4b, activating the isocyanate. Organotin compounds follow a similar path to that of the acids.…”