Control synthesis of isocyanate and alkoxy‐silane terminated macromers

Abstract

AbstractThe kinetics of the reactions in bulk of 4,4′‐dicyclohexyl methane diisocyanate (H12 MDI) and 5‐isocyanato‐1,3,3‐trimethylcyclohexylmethyl isocyanate or isophorone diisocyanate (IPDI) with benzylic alcohol (BZA) and α‐hydroxy‐ω‐methyl ether‐terminated polyethylene oxide PEO (M̄w = 350) were studied by size exclusion chromatography (SEC) and 13C nuclear magnetic resonance (13C‐NMR). The substitution effect is exhibited in the case of H12 MDI reactivity. The kinetic constants were calculated by a numerical method. The second‐order kinetic mechanism was shown to be valid. In the IPDI case, the cycloaliphatic isocyanate group is shown to be more reactive than the aliphatic group in our conditions, without catalysis, in agreement with previous results from the literature, in our obtained by 1H‐and 13C‐NMR without any catalyst. The reactivity ratio is found to be on the order of 3. This difference in reactivity of the two isocyanate groups is used for the control synthesis of isocyanate and alkoxy‐silane‐terminated macromers.