Preparation and characterization of polyurethane hybrids from reactive polyhedral oligomeric silsesquioxanes

Hybrid polyester resins containing polyhedral oligomeric silsesquioxanes (POSS), and their polyurethanes were prepared using reactive POSS as a substitution for partial diol monomer. They were investigated by FT-IR, rheometry, dynamic mechanical analysis, wide-angle X-ray diffraction contact-angle measurement, atomic force microscopy, and thermogravimetric analysis, respectively. The results showed that the hybrid polyester-POSS resins had a shear thinning behaviour and the more the POSS was embedded, the stronger the shear thinning behaviour, and the higher the viscosity. Incorporation of POSS could increase the glass transition temperature and thermal stability and decrease the surface free energy of the polyurethanes. When the POSS content was relatively high, the POSS molecules in hybrid polyurethane-POSS had a strong self-assembling ability to form nanocrystalline domains.