Physical Properties of Low-Molecular Weight Polydimethylsiloxane Fluids

Abstract

Physical property measurements including viscosity, density, thermal conductivity, and heat capacity of low-molecular weight polydimethylsiloxane (PDMS) fluids were measured over a wide temperature range (˗50 o C to 150 o C when possible). Properties of blends of 1 cSt and 20 cSt PDMS fluids were also investigated. Uncertainties in the measurements are cited. These measurements will provide greater fidelity predictions of environmental sensing device behavior in hot and cold environments. NOMENCLATURE CO 2 Carbon dioxide ESD Environmental sensing device LA Launch accelerometer NSC National Security Campus N 2 Nitrogen PDMS Polydimethylsiloxane VTC Viscosity temperature coefficient Figure 16. Room temperature viscosity of PDMS fluids measured in this report, by S. Wells [2] and predicted using a simple mixing rule [12].

Technical Note: T1 and T2 and complex permittivities of mineral oil, silicone oil, and glycerol at 0.35, 1.5, and 3 T

“…A12728, CAS 63148‐62‐9, $200/L, MW: 3784 g/mol, density: 0.96 g/cm 3 , viscosity: 52.4 mm 2 /s @ 25°C, Supplier: Fisher Scientific, Hampton, NH), and glycerol (Fisher Scientific, Stock No. S25342B, CAS 56‐81‐5, $23/L, MW: 92 g/mol, density: 1.25 g/cm 3 , Supplier: Fisher Scientific) . T 1 and T 2 were compared to the ACR large phantom electrolyte liquid (10 mM NiCl 2 and 75 mM NaCl in water) and deionized water measured values .…”

PEG/PPG-PDMS-Adamantane-Based Crosslinked Terpolymer Using the ROMP Technique to Prepare a Highly Permeable and CO2-Selective Polymer Membrane

“…Further, decreasing the gel fraction was expected to lower the density of the membranes through the formation of more voids in the crosslinked structure, but it tended to increase with a decrease in gel fraction values ( Table 1 ). This is attributed to the reduced content of highly flexible PDMS units, which are known to be low-density [ 39 ]. Moreover, it was found that the poly(NB-Ad) had a higher density value than x(PEG/PPG: PDMS:Ad)s, strongly suggesting that the density of our crosslinked membranes is highly dependent on the density of each component used.…”

Electrical Conductivity and Viscosity in Binary Organic Liquid Mixtures: Participation of Molecular Interactions and Nanodomains

“…Thus, the schematic in Figure 10a shows intercalated octanoic acid molecules within the silicone oil (polydimethylsiloxane, PDMS) matrix, hindering the flow of polymer molecules past each other. (Note that the molecular weight of PDMS comprising the 20 cSt silicone oil (≈2000 g/mol [53]) used in this study is well below the molecular weight at which chain entanglement is first observed, ≈27,500 [68]). behavior is an indication of molecular structuring in the binary mixtures, with the mole ratio of ≈0.67 again indicating the optimum packing of the components to achieve the greatest change in viscosity.…”

“…It is important to note that the electrical conductivity of 1-octanol is around four to five orders of magnitude greater than the other liquids. The dynamic viscosity is highest for silicone oil, which comprises approximately 30 dimethylsiloxane (DMS) repeat units, i.e., H 3 C-[Si(CH 3 ) 2 -O] n -CH 3 , with a molecular weight of ≈2000 [53]. The surface tensions of the liquids are all similar, the relatively low values indicating that the liquids are dominated by dispersion interactions; the slightly higher surface tension for 1-octanol indicates a relatively small degree of polar (including hydrogen bonding) character (also consistent with its dielectric constant value of ≈10 and dipole moment ≈1.7 D in dilute solution [16].…”