Morphology evolution and associated curing kinetics in reactive blends

Morphology evolution and associated curing kinetics of reactive ternary blends have been investigated using spectroscopic, microscopic, and thermal methods. These blends, used to model one-part adhesive, usually incorporate functionalized amorphous polyethers, functionalized crystallizable polyesters and relatively immobile polyacrylates. As expected, the formation of morphological features can be manipulated by altering both blend composition and thermal history. In our case, the functional groups are isocyanates. Therefore, the curing mechanism of these functionalized polymers is the reaction of isocyanate with ambient water. As expected, the reaction kinetics in these blends is strongly dependent on the morphological features such as size of phase-separated domains, the degree of polyester crystallinity and the crystallite size. Our study has also revealed that the overall curing rates of these reactive ternary blends are dominated by the amorphous mobile polyether component.