PPDO-PU/Montmorillonite Nanocomposites Prepared by Chain-Extending Reaction: Thermal Stability, Mechanical Performance and Rheological Behavior

Abstract A two-step approach was employed to prepare Poly(p-dioxanone)-PU/organic montmorillonite (PPDO-PU/OMMT) nanocomposites. In the first step, PPDO diol prepolymers with different molecular weights were synthesized by ring-opening polymerization of p-dioxanone; in the second step, PPDO-PU/OMMT nanocomposites were prepared by coupling PPDO diol melt swollen with organo-modified MMT (OMMT), using 1,6-hexamethylene diisocyanate (HDI) as the chain-extender. The intercalated-exfoliated coexistence morphology of nanocomposites was determined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Thermogravimetric analysis (TG), high-pressure capillary rheometer, and mechanical test were performed to investigate the properties of the nanocomposites. The results showed that the thermal stability and mechanical performance of nanocomposites were greatly improved compared to that of pure PPDO. The enhancement of shear viscosity and low temperature sensitivity of the nanocomposite melts enabled it to produce thin films by blowing process successfully. Keywords: Chain extendingNanocompositeOrganic montmorillonitePoly (p-dioxanone-urethane)Properties ACKNOWLEDGMENTS This work was supported financially by the National Science Foundation of China (20504022) and the program for New Century Excellent Talents in University (NCET-07-0586). The authors also thank Prof. In-Joo Chin and Mr. Shi-Li Quan in Inha University (Korea) for the help of the TEM measurements.