Synthesis of ferrocenyl-containing silicone rubbers via platinum-catalyzed Si-H self-cross-linking

Self-cross-linkable ferrocenyl-containing polymethylhydrosiloxanes were synthesized. Karstedt's catalyst and cis-[PtCl2(BnCN)(2)] were examined as cross-linking catalysts at room temperature for the reaction between Si-H groups of the ferrocenyl-containing polymethylhydrosiloxanes. Cis-[PtCl2(BnCN)(2)] is an effective catalyst that allows cross-linked ferrocenyl-containing silicones (silicone rubbers) to be obtained with no visible mechanical defects (bubbles or cracks) compared with Karstedt's catalyst. The ferrocene content of the ferrocenyl-containing silicone rubbers was found to be approximately 50 wt.% by energy-dispersive X-ray analysis. Compared with cross-linked non-modified polymethylhydrosiloxanes, the ferrocenyl-containing silicone rubbers exhibited improved tensile properties (the tensile strength increased from 0.47 to 0.75 MPa) and a 1.5-2.5 times lower cross-linking degree. The surface resistivity of the ferrocenyl-containing silicone rubbers (50 wt.% ferrocenyl units) was approximately 7 x 10(9) omega/, which was 10,000 times lower than that of pure polymethylhydrosiloxane. The obtained flexible electroactive ferrocenyl-containing silicone rubbers can potentially be applied as coatings for electronic and electrostatic-sensitive devices, interfaces, and sensors.