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The present study describes the effect of NCO/OH ratio and addition of Cerium (Ce)‐Zirconium (Zr) mixed oxide nanoparticles on the properties of Hyperbranched Polyurethane Urea (HBPUU) Coatings. Initially a hydroxyl terminated hyperbranched polymer (HTBP) was synthesized through A3 + CB2 approach. The HTBP and Ce‐Zr nanopowder dispersed HTBP, both were reacted with hexamethylene diisocyanate (HDI) separately; at various NCO/OH eq. ratios to get different NCO terminated HBPU and HBPU/Ce‐Zr hybrid prepolymers. These prepolymers were used for the preparation of HBPUU and HBPUU/Ce‐Zr hybrid coating films through moisture curing. The techniques such as 1H NMR, 13C NMR, FT‐IR, and XRD have been used for structural information while Dynamic mechanical and thermal analyzer (DMTA), Thermogravimetric analysis (TGA) and Universal testing machine (UTM) have been used for evaluation of thermo‐mechanical properties. The combined spectroscopic investigations results indicate the formation of HBPUU network with a degree of branching of 76% while FT‐IR deconvolution results indicates the formation of more hydrogen bonded structure with increasing NCO/OH ratio. The XRD and FT‐IR studies confirm the presence of Ce‐Zr mixed nanoparticles in the HBPUU hybrids. As per TGA and DMTA analysis the thermal stability, char residue, storage modulus (E', material stiffness) and glass transition temperature (Tg), increases with increasing NCO/OH ratio and Ce‐Zr nanoparticle loading in HBPUU coatings. In general, UTM data suggest that the tensile strength increases and per cent elongation at break decreases with increasing the NCO/OH ratio and addition level of nanoparticles in HBPUU coatings. Copyright © 2009 John Wiley & Sons, Ltd.

Pervanadyl (VO 2 + ) complexes with N-(aroyl)-N'-(picolinylidene)hydrazines (HL = Hpabh, Hpath and Hpadh; H stands for the dissociable amide hydrogen) are described. The Schiff bases were obtained by condensation of 2-pyridine-carboxaldehyde with benzhydrazide (Hpabh), 4-methylbenzhydrazide (Hpath) and 4-dimethylaminobenzhydrazide (Hpadh), respectively. The reaction of [VO(acac) 2 ] and HL in acetonitrile in air affords the complexes of general formula [VO 2 L]. The diamagnetic nature and EPR silence confirm the +5 oxidation state of vanadium in these complexes. Infrared spectra of the complexes are consistent with the enolate form of the coordinated ligands. Electronic spectra show charge transfer bands in the range 486±233 nm. The complexes are redox active and display an irreversible reduction (±0.64 to ±0.72 V vs. Ag/AgCl). The crystal structures of all the complexes have been determined. In each complex, the metal centre is in a distorted trigonal-bipyramidal N 2 O 3 coordination sphere formed by the pyridine-N, the imine-N and the deprotonated amide-O donor L ± and two oxo groups. The planar ligand satisfies one equatorial and two axial positions. The other two equatorial positions are occupied by the two oxo groups. In the solid state, the molecules of each of the three complexes form a chain-like arrangement via the azomethine-H´´´oxo interactions. Interchain weak p-p interactions lead to two dimensional networks for [VO 2 (pabh)] and [VO 2 (path)]. On the other hand, [VO 2 (padh)] forms a two-dimensional network through interchain N-methyl-H´´´oxo interactions.Mononukleare Pervanadyl(VO 2 + )-Komplexe mit dreiza È hnigen Schiff'schen Basen: Strukturaufbau via C±H´´´oxo-und p-p-Wechselwirkungen Inhaltsu È bersicht. Pervanadyl(VO 2 + )-Komplexe mit N-(aroyl)-N'-(picolinyiden)hydrazinen (HL = Hpabh, Hpath und Hpadh; H steht fu È r abdissoziierbaren Amidwasserstoff) werden beschrieben. Die Schiff'schen Basen wurden durch Kondensationsreaktionen von 2-Pyridincarboxylaldehyd mit Benzhydrazid (Hpabh), 4-Methylbenzhydrazid (Hpath) bzw. 4-Dimethylaminobenzhydrazid (Hpadh) erhalten. Die Reaktion von [VO(acac) 2 ] und HL in Acetonitril an Luft ergibt die Komplexe der allgemeinen Formel [VO 2 L]. Die diamagnetische Natur und fehlende EPR-Signale besta È tigen den Oxidationszustand +5 des Vanadiums in diesen Komplexen. Die IR-Spektren der Komplexe stehen in Ûbereinstimmung mit der Enolat-Form der Liganden. Die Elektronenspektren zeigen Chargetransfer-Banden im Bereich von 486 bis 233 nm. Die Komplexe sind redox-aktiv und zeigen eine irreversible Reduktion (±0,64 bis ±0,72 V vs. Ag/AgCl). DieKristallstrukturen aller Verbindungen wurden bestimmt. In jedem Komplex liegt das Metallatom in einer verzerrt-trigonal-pyramidalen N 2 O 3 -Koordinationsspha È re vor, die aus dem Pyridin-N-Atom, dem Imin-N-Atom und dem deprotonierten Amid-O-Atom des Donors L ± und zweier Oxogruppen gebildet wird. Die planaren Liganden besetzen eine a È quatoriale und zwei axiale Positionen. Die anderen zwei a È quatorialen Positionen werden durc...