SYNTHESIS AND CHARACTERIZATION OF POLYURETHANE-POSS DISPERSIONS AND FILMS

摘要

Polyurethane dispersions were prepared with 4-10 wt % of functionalized polyhedral oligomeric silsesquioxanes (POSS) using the acetone process. The use of acetone as the initial polymerization solvent allowed for the facile incorporation of both diamino and dihydroxy functional POSS monomers, in a homogeneous reaction environment. After addition of water and removal of the acetone, stable dispersions with uniform particle sizes were obtained. The incorporation of the POSS monomers did not have a significant effect on dispersion solution properties. However the physical properties of the isolated solid polymers did show significant changes, with notable increases in modulus, Tg, complex viscosity and surface hydrophobicity. These changes are attributed to the incorporation of the POSS residues into the polyurethane hard segment domains found with this type of formulation. There was no sign of any gross phase heterogeneity caused by the inclusion of POSS moieties detected by either thermal characterization or wide angle x-ray scattering.