The A6 + B2 approach to hyperbranched polymers based on the dendrimer (A6) as a multifunctional monomer and bis(cyclopentadienone)s (B2) holds promise for the one-pot synthesis of well-defined polymers with perfect dendritic fragments in the backbone.

A new family of Ni-, Co-, and Cr-doped Zn-containing magnetic oxide nanoparticles (NPs) stabilized by polyphenylquinoxaline (PPQ) and hyperbranched pyridylphenylene polymer (PPP) has been developed. These NPs have been synthesized by thermal decomposition of Zn and doping metal acetylacetonates in the reaction solution of preformed magnetite NPs, resulting in single-crystal NPs with spinel structure. For the PPQ-capped NPs, it was demonstrated that all three types of metal species (Fe, Zn, and a doping metal) reside within the same NPs, the surface of which is enriched with Zn and a doping metal, while the deeper layers are enriched with Fe. The Cr-doped NPs at the high Cr loading are an exception due to favored deposition of Cr on magnetite located in the NP depth. The PPP-capped NPs exhibit similar morphology and crystallinity; however, the detailed study of the NP composition was barred due to the high PPP amount retained on the NP surface. The catalyst testing in syngas conversion to methanol demonstrated outstanding catalytic properties of doped Zn-containing magnetic oxides, whose activities are dependent on the doping metal content and on the stabilizing polymer. The PPP stabilization allows for better access to the catalytic species due to the open and rigid polymer architecture and most likely optimized distribution of doping species. Repeat experiments carried out after magnetic separation of catalysts from the reaction mixture showed excellent catalyst stability even after five consecutive catalytic runs.

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Here we use model nanocomposites based on polystyrene and polyphenylene dendrimers to show both theoretically and experimentally that inclusion of rigid nanoparticles of 2.3–5 nm size into the polymer leads to a negligible glass transition temperature (Tg) increase.

We report hydrogenation of furfural (FF) to furfuryl alcohol (FA) with novel Pt-and Pd-containing magnetite nanoparticles (NPs) stabilized by polyphenylquinoxaline (PPQ) and hyperbranched pyridylphenylene polymer (PPP). FF is one of the major ingredients of biooil produced by biomass pyrolysis, while FA is a source of value-added chemicals, thus, creating a sustainable path from biomass to important compounds. We demonstrate that catalytic NPs (Pt 0 or Pd 0 ) of approximately 3 nm in diameter form in the polymer shells of magnetite NPs and the catalysts are magnetically recoverable. The search for optimal reaction conditions of the FF hydrogenation revealed that the highest selectivity is obtained at 120 8C and 6 MPa hydrogen pressure in i-propanol as solvent. The solvent effect is due to combination of good FF solubility and accessibility of catalytic NPs for the FF adsorption. A comparison of the catalytic activities of the Pd-containing magnetite NPs stabilized by PPQ and PPP validates the advantages of the open and rigid structure of the hyperbranched PPP vs. linear PPQ. For Pdcontaining magnetite NPs stabilized by PPP, the high selectivity to FA of 99.3% at nearly 100% FF conversion was achieved at a remarkable activity of 871 min À1 and high catalyst stability.