Siliconas

DMS-H31: Hydride Terminated PDMS, 1,000 cSt (Telechelic Functional Fluid) Hydride terminated silicones are chain extenders for vinyl-addition silicones, enabling low-viscosity, high elongation formulations. They are also intermediates for functionally terminated silicones. DMS-H31 Properties Viscosity: 1,000 cStMolecular Weight: 28,000 g/molWt.% Hydride: 0.007

DMS-S33: Silanol Terminated PDMS, 3,500 cSt (Telechelic Functional Fluid) Terminal silanol groups render polydimethylsiloxanes susceptible to condensation under both mild acid and base conditions. They are intermediates for most room temperature vulcanizeable (RTV) condensation cure silicones. The reactivity of silanol fluids is utilized in applications other than RTVs. Low viscosity silanol fluids are employed as filler treatments and structure control additives in silicone rubber compounding. Intermediate viscosity (1,000-10,000 cSt) fluids can be applied to textiles as durable fabric softeners. High viscosity silanol terminated fluids form the matrix component in tackifiers and pressure sensitive adhesives. DMS-S33 Properties Viscosity: 3,500 cStMolecular Weight: 43,500 g/molWt.% OH: 0.8OH (eq/kg): 0.045-0.050

Siloxane-Based Silane Reducing Agent Organosilanes are hydrocarbon-like and possess the ability to serve as both ionic and free-radical reducing agents. These reagents and their reaction by-products are safer and more easily handled and disposed than many other reducing agents. The metallic nature of silicon and its low electronegativity relative to hydrogen lead to polarization of the Si-H bond yielding a hydridic hydrogen and a milder reducing agent compared to aluminum-, boron-, and other metal-based hydrides. A summary of some key silane reductions are presented in Table 1 of the Silicon-Based Reducing Agents brochure. Pendant Functional Fluid; polyMethylHydrosiloxanes, TMS Terminated MethylHydrosiloxane homopolymers are used as water-proofing agents, reducing agents and as components in some foamed silicone systems. Poly(methylhydrosiloxane); Methyl hydrogen siloxane; Polysiloxanes, methyl hydrogen; Siloxanes and silicones, methyl hydrogen Viscosity: 15-25 cStMolecular Weight: 1,400-1,800 g/molMol% Hydride: 100Reduces lactones to lactolsReduces aldehydes, ketones, esters, lactones, triglycerides and epoxides to alcohols with zinc hydride catalysisWith titanium tetraisopropoxide catalysis carries out reductive amination of ketones and aldehydes and the reduction of acids or esters to 1° alcoholsWith TBAF catalysis selectively reduces aldehydes over ketonesUsed to generate tri-n-butyltin hydride ‘in-situ’ and in a one-pot hydrostannylation/Stille coupling sequenceReduces esters to alcoholsExtensive review of silicon based reducing agents: Larson, G.; Fry, J. L. "Ionic and Organometallic-Catalyzed Organosilane Reductions", Wipf, P., Ed.; Wiley, 2007