Silicones

PDV-1625: Vinyl Terminated Diphenylsiloxane-Dimethylsiloxane Copolymer (Telechelic Functional Fluid)
These fluids are most often employed in 2-part addition cure silicone elastomers where special thermal or optical properties are required.
PDV-1625 Properties
Viscosity: 500 cStMolecular Weight: 9,500 g/molVinyl (eq/kg): 0.19-0.23Refractive Index: 1.465

DMS-H25: Hydride Terminated PDMS, 500 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-H25 Properties
Viscosity: 500 cStMolecular Weight: 17,200 g/molWt.% Hydride: 0.01

DMS-R18: Methacryloxypropyl Terminated PDMS, 50-90 cSt (Telechelic Functional Fluid)
Methacrylate and Acrylate functional siloxanes undergo the same reactions generally associated with methacrylates and acrylates, the most conspicuous being radical induced polymerization. Unlike vinylsiloxanes which are sluggish compared to their organic counterparts, methacrylate and acrylate siloxanes have similar reactivity to their organic counterparts. The principal applications of methacrylate functional siloxanes are as modifiers to organic systems. Upon radical induced polymerization, methacryloxypropyl terminated siloxanes by themselves only increase in viscosity. Copolymers with greater than 5 mole % methacrylate substitution crosslink to give non-flowable resins. Acrylate functional siloxanes cure greater than ten times as fast methacrylate functional siloxanes on exposure to UV in the presence of a photoinitiator such as ethylbenzoin.
Oxygen is an inhibitor for methacrylate polymerization in general. The high oxygen permeability of siloxanes usually makes it necessary to blanket these materials with nitrogen or argon in order to obtain reasonable cures.
DMS-R18 Properties
Viscosity: 50-90 cStMolecular Weight: 4,500-5,500 g/molRefractive Index: 1.409

DMS-S21: Silanol Terminated PDMS, 90-120 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-S21 Properties
Viscosity: 90-120 cStMolecular Weight: 4,200 g/molWt.% OH: 0.8-0.9OH (eq/kg): 0.47-0.53

DMS-V51: Vinyl Terminated PDMS, 100,000 cSt (Telechelic Functional Fluid)
Vinyl terminated polymers are most often employed in 2-part addition cure silicone elastomers.
DMS-V51 Properties
Viscosity: 100,000 cStMolecular Weight: 140,000 g/molWt.% Vinyl: 0.03-0.05Vinyl (eq/kg): 0.016-0.018