We have synthesized a new polyhedral oligomeric silsesquioxane (POSS) containing eight phenol functional groups and copolymerized it with phenol and formaldehyde to form novolac-type phenolic/POSS nanocomposites exhibiting high thermal stabilities and low surface energies. Our DSC results indicate that the glass transition temperature of these nanocomposites increased initially upon increasing their POSS content, but then decreased at POSS content above 10 wt.-%, presumably because of the formation of relatively low molecular weight species and POSS aggregation as evidenced from MALDI-TOF mass analyses. Our TGA analyses indicated that the 5-wt.-%-mass-loss temperatures (T d ) increased significantly upon increasing the POSS content because the incorporation of the POSS led to the formation of an inorganic protection layer on the nanocomposite's surface. XPS and contact angle data provided positive evidence to back up this hypothesis. In addition, contact angle measurements indicated a significant enhancement in surface hydrophobicity after increasing the POSS content.Syntheses procedures of phenolic/OP-POSS nanocomposites.

The hydrophilicity of bis(3-allyl-3,4-dihydro-2H-1,3-benzoxazinyl)isopropane(B-ala) polybenzoxazine film and superhydrophobic polybenzoxazine-hybrid surface can be controlled through UV exposure to change the ratio of intra- to intermolecular hydrogen bonds. A fraction of the intramolecular hydrogen bonding of the as-cured sample will convert into intermolecular hydrogen bonding upon UV exposure and thus results in an increase of hydrophilicity. This simple method allows for manipulating the hydrophilicity at selected regions on a superhydrophobic polybenzoxazine hybrid surface to create a patterned surface with superhydrophobic and superhydrophilic regions. Additionally, we have found that the superhydrophobic polybenzoxazine-silica hybrid surface exhibits good adhesion of water droplets after UV exposure, which can be served as a "mechanical hand" to transfer water droplets from a superhydrophobic surface to a hydrophilic one.

We have synthesized a polyhedral oligomeric silisesquioxane (POSS) derivative containing eight acetoxystyryl functional groups [octa(acetoxystyryl)octasilsesquioxane (AS‐POSS)] and then blended it with phenolic resin to form nanocomposites stabilized through hydrogen bonding interactions between the phenolic resin's hydroxyl group and the AS‐POSS derivative's carbonyl and siloxane groups. One‐ and two‐dimensional infrared spectroscopy analyses provided positive evidence for these types of hydrogen bonding interactions. In addition, we calculated the interassociation equilibrium constant, based on the Painter–Coleman association model (PCAM), between phenolic resin and POSS indirectly from the fraction of hydrogen‐bonded carbonyl groups; quantitative analyses indicate that the hydroxyl–siloxane interassociation from the PCAM is entirely consistent with the classical Coggesthall and Saier (C and S) methodology. From a thermal analysis, we observed that the miscibility between phenolic and AS‐POSS occurs at a relatively low AS‐POSS content, which characterizes this mixture as a polymer nanocomposite system. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 673–686, 2006

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