Back to Search
Start Over
bis-Nitrile and bis-Dialkylcyanamide Platinum(II) Complexes as Efficient Catalysts for Hydrosilylation Cross-Linking of Siloxane Polymers
- Source :
- Molecules, Vol 21, Iss 3, p 311 (2016)
- Publication Year :
- 2016
- Publisher :
- MDPI AG, 2016.
-
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.
Details
- Language :
- English
- ISSN :
- 14203049
- Volume :
- 21
- Issue :
- 3
- Database :
- Directory of Open Access Journals
- Journal :
- Molecules
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.8851dae0ed354b6b9d533072abbf060b
- Document Type :
- article
- Full Text :
- https://doi.org/10.3390/molecules21030311