Preparation and characterization of polyurethane-imide/kaolinite nanocomposite foams

Abstract

A novel polymer/kaolinite nanocomposite based on polyurethane-imide (PUI) foams was prepared by in situ polymerization. The PUI foams were synthesized via the reaction between isocyanate terminated polyimide prepolymers and polyether polyol. The kaolinite was modified with an intercalating agent of potassium carbonate. XRD analyses of the intercalated kaolinite and the PUI/kaolinite nanocomposite foams indicate that both intercalated and exfoliated structures are formed. The cell structure, cell size distribution, thermal stability and mechanical properties of the PUI/kaolinite nanocomposite foams are characterized by SEM, TG and an electronic universal testing method. Kinetics of thermal degradation and thermal aging life of the nanocomposite foams are investigated and forecasted compared with those of the pure PUI foams. The results show that addition of the kaolinite significantly improves the heat resistance and mechanical properties. However, the functional groups of PUI foams don't change obviously.