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bis-Nitrile and bis-Dialkylcyanamide Platinum(II) Complexes as Efficient Catalysts for Hydrosilylation Cross-Linking of Siloxane Polymers

Regina M Islamova, Mikhail V Dobrynin, Daniil M Ivanov, Andrey V Vlasov, Elena V Kaganova, Galina V Grigoryan, Vadim Yu Kukushkin

Molecules. 2016 Mar 5;21(3):311.

PMID: 26959003

Abstract:

cis- and trans-Isomers of the platinum(II) nitrile complexes [PtCl2(NCR)2] (R = NMe2, N(C₅H10), Ph, CH2Ph) were examined as catalysts for hydrosilylation cross-linking of vinyl-terminated polydimethylsiloxane and trimethylsilyl-terminated poly(dimethylsiloxane-co-ethylhydrosiloxane) producing high quality silicone rubbers. Among the tested platinum species the cis-complexes are much more active catalysts than their trans-congeners and for all studied platinum complexes cis-[PtCl2(NCCH2Ph)2] exhibits the best catalytic activity (room temperature, c = 1.0 × 10(-4) mol/L, τpot-life 60 min, τcuring 6 h). Although cis-[PtCl₂(NCCH2Ph)2] is less active than the widely used Karstedt's catalyst, its application for the cross-linking can be performed not only at room temperature (c = 1.0 × 10(-4) mol/L), but also, more efficiently, at 80 °C (c = 1.0 × 10(-4)-1.0 × 10(-5) mol/L) and it prevents adherence of the formed silicone rubbers to equipment. The usage of the cis- and trans-[PtCl2(NCR)2] complexes as the hydrosilylation catalysts do not require any inhibitors and, moreover, the complexes and their mixtures with vinyl- and trimethylsilyl terminated polysiloxanes are shelf-stable in air. Tested catalysts do not form colloid platinum particles after the cross-linking.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP68037592 Poly(dimethylsiloxane-co-methylhydrosiloxane), trimethylsilyl terminated Poly(dimethylsiloxane-co-methylhydrosiloxane), trimethylsilyl terminated 68037-59-2 Price
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