Sodium montmorillonite intercalated with poly(ethylene glycol): a modifier of reactive hot-melt polyurethane adhesive

We have examined the effects of a sodium montmorillonite (Na-MMT) intercalated with poly(ethylene glycol) (PEG) on the properties of a reactive hot melt adhesive (RHA) based on polyurethane pre-polymer with terminal isocyanate groups. The bond strengths of the RHA, from the initial to final time period after application, were enhanced and the set time was reduced by the addition of 1–3 phr Na-MMT intercalated with PEG (Na-MMT/PEG). The modifier increased the viscosity and a pseudo-solid-like behavior at low shear rates when subjected to a dynamic shear stress. Further, both the tensile modulus and tensile strength of cured RHA films were improved by the reinforcing effect of Na-MMT. The X-ray diffraction pattern of RHA showed that the gallery of Na-MMT was intercalated with PEG segment.