Univerzita Pardubice Fakulta chemicko- technologická

Univerzita Pardubice

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Publikace detail

Vanadium-based driers for alkyd coatings

Autoři: Honzíček Jan | Preininger Ondřej | Kalenda Petr | Vinklárek Jaromír

Rok: 2016

Druh publikace: ostatní - přednáška nebo poster

Strana od-do: nestránkováno

Tituly:

Jazyk	Název	Abstrakt	Klíčová slova
eng	Vanadium-based driers for alkyd coatings	Alkyd resins modified with polyunsaturated fatty acids (e.g. linoleic acid, linolenic acid) are well-established paints used in modern organic coating technologies. Presence of double bonds in the binder molecules enables the reaction with air oxygen to give firm coating with three-dimensional polymeric structure. This radical process is catalyzed with transition metal compounds, so-called driers, those significantly reduce binder drying time and improves physical properties of resulting polymeric film. Although cobalt(II) carboxylates are the most powerful alkyd driers, their use is going to be restricted owing to their toxicity. Our scrutiny for new highly active, ecologically-friendly and inexpensive drying agents led us to oxovanadium(IV) compounds bearing various chelating ligands (VO-1, VO-2, VO-3), see Figure 1. These species show low overall toxicity and our investigation reveals an excellent drying activity in solvent-borne alkyd binders. Hence, at low metal concentration (0.03 wt.% in dry matter content), the performance of the vanadium compounds VO-1 and VO-2 resembles commertial cobalt(II) 2-ethylhexanotate at dosage recommended by supplier (0.1 wt.%). The low solubility of the parent oxovanadium(IV) acetylacetonate (VO-1) was overcome by targeted modification of the chelating ligands. Hence, species with a long alkyl tail (VO-2) are well soluble in various alkyd formulations including high-solids systems. The autoxidation process was studied in detail by time-dependent infrared spectroscopy. The stability of the active oxovanadium(IV) species during the drying process was evidenced by electron paramagnetic resonance.