Dimethylpolysilane

• CAS: 28883-63-8
• Catalog Number: ACM28883638
• Category: Main Products
• Molecular Formula: C2H6Si
• Appearance: Off-white powder

Case Study

Development of a High-Performance Palladium Catalyst Supported on Poly(dimethylsilane) for Continuous-Flow Hydrogenation

Kobayashi, Shū, et al. ChemCatChem 7.24 (2015): 4025-4029.

In this work, poly(dimethylsilane) (PDMSi) was used as a non-aromatic polymeric ligand/support component to prepare Pd catalysts (Pd/PDMSi-Al2O3) that show higher hydrogenation activity than conventional Pd/C and perform robustly in continuous-flow hydrogenation. The catalyst was applied to a range of substrates - neat liquid alkenes, dissolved solids, vegetable oils, squalenes and phosphatidylcholine - at gram→kilogram scales under mild conditions, demonstrating practical scalability and broad substrate scope.
Preparation of Pd/DMPSi-Al2O3: Pd(OAc)2 was combined with poly(dimethyl)silane and Al2O3 in toluene at low temperature under argon (example scale: Pd(OAc)2 13.5 g, PDMSi 100 g, Al2O3 900 g). After an initial stirring period (~50 min at ~0 °C) methanol (100 mL) was added and the reaction continued (~70 min at ~0 °C). The resulting solid was collected, washed (MeOH, water, acetone) and vacuum-dried to yield the Pd/PDMSi-Al2O3 catalyst (1035.5 g). Palladium loading was determined by ICP after acid digestion as 56.6 mmol/g.
Continuous-Flow Hydrogenation: 916.0 mg of Pd/PDMSi-Al2O3 was packed in a column heated to 50 °C. Ethyl cinnamate (neat) was pumped through the column (reported pump rate 150 mL/min) with simultaneous H2 flow (reported 30.2 mL/min, ≈1.5 equiv relative to substrate). After stabilization, product was collected over a multi-hour run (5 h) and an isolated product mass (reported 46.4 g of hydrogenated product) was obtained and characterized by ¹H NMR for purity.

Poly(dimethylsilane) Nanocomposites Reinforced with a 3D rGO/SWCNT Bicontinuous Framework for High-Performance EMI Shielding

Zhao, Sumin, et al. ACS applied materials & interfaces 10.31 (2018): 26723-26732.

This study described the development and performance of a poly(dimethylsilane) (PDMS)-based nanocomposite made by backfilling PDMS into a preformed three-dimensional reduced-graphene-oxide / single-wall carbon-nanotube (rGO/SWCNT) aerogel scaffold; the resulting materials achieved a noteworthy electrical conductivity of 1.2 S/cm, an electromagnetic-interference (EMI) shielding effectiveness of ≈31 dB across the X-band at an ultralow total filler loading of 0.28 wt%, and substantially improved mechanical properties (for example, a 233% increase in compression strength versus neat PDMS), demonstrating the composite concept's ability to combine light weight, flexibility, conductivity and mechanical robustness.
Three-dimensional rGO/SWCNT aerogels were fabricated by a sol-gel self-assembly induced via chemical reduction: graphene-oxide (GO) dispersion (3 mg/mL) and SWCNTs were homogenized, reduced with L-ascorbic acid, thermally treated through partial reduction and freeze-thaw steps, dialyzed, freeze-dried to yield a GCA aerogel, and then thermally annealed at 800 °C under N2 to produce a higher-conductivity TGCA.
PDMS backfilling and composite fabrication: PDMS composites were produced by vacuum backfilling: a diluted PDMS solution (2 g PDMS base+curing agent, 10:1 w/w, in 10 mL n-hexane) was used to infiltrate TGCA aerogels under vacuum for 60 min to remove bubbles and solvent, followed by thermal curing at 60 °C for 4 h. The resulting composites (PTGCAx) retained the 3D conductive framework while forming a continuous PDMS phase around the rGO/SWCNT network; filler loadings were ultralow (reported total filler ≈0.28 wt% for the best performing sample).