Preparation and thermal characterization of poly(2‐vinylpyridine) copolymers coordinated to Cr nanoparticles

Abstract

In this study, polystyrene-block-poly(2-vinylpyridine), PS-b-P2VP, polyisoprene-block-poly(2-vinylpyridne), PI-b-P2VP and poly(methyl metacrylate)-block-poly(2-vinylpyridine), PMMA-b-P2VP, coordinated to Cr metal were synthesized and characterized by Fourier transform infrared, transmission electron microscopy and direct pyrolysis mass spectrometry techniques. Both thermal degradation mechanism and thermal stability of P2VP blocks were affected by the coordination of Cr nanoparticles to nitrogen of pyridine rings. Thermal decomposition of P2VP blocks was started by loss of pyridine units leaving an unsaturated and/or crosslinked polymer backbone that degraded at relatively high temperatures. Incorporation of Cr metal did not noticeably influence thermal behavior of PS and PI blocks. However, increase in thermal stability of PMMA block was detected and associated with inhibition of the interactions between carbonyl groups of MMA chains with nitrogen atom of pyridine ring as a consequence of coordination to metal.

Electron-Rich Gold Clusters Stabilized by Poly(vinylpyridines) as Robust and Active Oxidation Catalysts

“…Au NPs (20 nm) embedded within the microparticles of poly­( N -isopropylacrylamide) (PNIPAM) were highly robust and active for the C–C bond-forming reactions . In this work, we investigated the potential of poly­(vinylpyridines), which have been used as templates for preparing metal and metal oxide NPs, − as effective stabilizers of Au clusters for their catalytic application. So far, poly­(vinylpyridine) and its copolymers have been used to tune the diameter of Au NPs in the range of 20–130 nm to enhance the long-term stability of Au NPs (4–7 nm) against aggregation and to produce anisotropic Au nanostructures of various shapes, such as octahedron, decahedron, tetrahedron, triangle, and triangular prism .…”