In manufacturing and chemical processes, mainly in anhydrous systems, a small addition of poly(dimethylsiloxane) prevents foaming, e.g., in oil production. Properly selected viscosity makes it possible to use PDMS for creating a coating and then separating rubber, plastic or metal castings from molds. Among others, they are used as a material for making microsystems, as MEMS precursors (microelectromechanical systems), and microfluidic components. Thanks to their high thermal stability, poly(dimethylsiloxanes) can be used in many industries. The unique chemical structures of poly(dimethylsiloxanes) ensure high chain mobility, which translates into high chemical stability, extremely low glass transition temperature of about −125 ∘ C and high gas permeability. Linear PDMS, poly(dimethylsiloxane), containing methyl groups (presented in Figure 2), is the most popular representative of this group of compounds.ġ D refers to the PDMS backbone units consisting of a silicon atom bound to two oxygen atoms and two methyl groups. Being structured this way, they show a number of valuable properties depending on the size of molecules, which distinguish them from organic materials. They consist of an alternating silicon-oxygen backbone chain and functional side groups. Polysiloxanes are organosilicon polymers with the general chemical formula n. It is therefore important to know the rheological properties of such oil. Depending on the degree of oil contamination and its viscosity, a damper is either approved for further use or regenerated during service. The most commonly used oil is stabilized poly(dimethylsiloxane) based oil produced by Bayer and Wacker. Polysiloxanes meet the above requirements, and that is why dampers are filled with silicon oils with viscosities of up to 1,000,000 cSt. Viscous torsional vibration damper: ( a) view with the cover closed, ( b) cross-section.Ī properly selected suppression medium should be non-toxic, show low compatibility, good chemical stability, high flash point, non-flammability, low sensitivity of viscosity to changes in temperature, resistance to cold and aging.
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