| Polymer based composites combined the good process property, electrical insulation and toughness of polymer with the properties of inorganic materials, such as high module, good dimension stability. To increase the interfacial action among the components in the components, the dispersion dimension which would be nanometer level or molecule level was desired, so the hybrids would be prepared. The properties of hybrids were improved greatly for the fine dispersion structure and strong interfacial interaction, while they owned some new special properties.Polyurethane is a multifunctional synthesis material. But there are still no reports about the research on polyurethane/ montmorllonite hybrids using aqueous polyurethane emulsion. The aqueous polyurethane emulsion uses water as solvent, so this polyurethane is superior not only in strength, tactile sensitivity to the wearer, but also in oil-resistance, flexibility, feeling and a relative low cost to the conventional polyurethane. By intercalating hydrophilic group COOH, the self-emulsifying polyurethane was prepared. The preparation process is well discussed and many effects such as hydrophilic group content, solid content and different chain-extenders on polyurethane emulsions are well studied.So based on the aqueous polyurethane emulsion we prepared and those polymer/ montmorllonite hybrids which were prepared through in situ polymerization, solution intercalation and melting intercalation, a new method named "latex blending and coagulating" was firstly put forward. Montmorllonite could be dispersed uniformly in water for the hydration of the action between the layers. The layers could be separated from each other to form a colloid and the layer would penetrate with the latex particle. The aqueous polyurethane emulsion was prepared and selected by means of molecule design. When the latex blended with the montmorllonite -water dispersion, a suspension could be formed. It could be coagulated by the diluted hydrochloric acid, and then the hybrids were prepared,which had strong interfacial action between the polymer and the clay layers by the ion bond. A new hybrid Polyurethane/ montmorllonite was prepared and characterized with XRD, TEM, DSC and FT-IR. The preparation process, morphology and their thermal and mechanical properties were studied. The results indicate that the montmorllonite could be used as a good reinforcing agent for polyurethane when layer was dispersed in nanometer level, and the hybrids' mechanical properties were improved. |
