Silicone lubricants

Noted Due to possible difficulty in maintaining the prescribed rate of temp rise and due to the formation of ice on the lid, results by this method for samples having fl p s below 32 F (0 C) may be somewhat unreliable. Trouble due to ice formation on the slide may be minimized by carefully lubricating the slide shutter with high-vacuum silicone lubricant... 

The spectrum of silicone lubricant, Appendix B (No. 27), illustrates some of the preceding absorptions. 

One useful blend currently being employed as a very effective silicone solvent on an industrial scale is a mixture of 80 vol % hydrocarbon heptane and 20 vol % perfluoropentane, called 1.-12808 (see Table 6.7). 1.-12808 is useful for applying silicone lubricants to numerous medical devices, such as needles, IV spikes, blood filters, and catheters. This mixture shows no flash point and no explosion limits in air. The presence of the more volatile PFC, relative to the HC,... 

We have already discussed the temperature dependence of the kinematic viscosity of silicones with relatively large viscosity values (silicone lubricants). The silicones concerned are chain polymers and in Table XIV the values of their F.V.T.I, is given together with their and x values. 

Silicone lubricants are widely used in a wide range of devices, including photographic, optical, sighting, X-ray equipment, etc. 

The checkers used a conventional vacuum line equipped with high-vacuum glass stopcocks that were lubricated with Dow Corning high-vacuum silicone lubricant. 

Teflon self-lubricating plastic bearings can be used in situations where a lubricant might contaminate the system. There are also a variety of nonoily lubricants such as silicone lubricant (usually dispensed as a spray) and molybdenum disulfide (suspended in petroleum distillates that evaporate to leave a dry coating). Molybdenum disulfide is an excellent alternative to graphite for lubrication of moving parts in a high-vacuum system. 

Solvent scour for the removal and emulsification of silicone lubricants typically used in spandex blends. 

Solvent scour for the removal of silicone lubricants from nylon/spandex fibers. 

All reactions are carried out using conventional vacuum-line techniques. Teflon-in-glass stopcocks and a silicone lubricant for ground-glass joints should be used because of the marked solubility of germanes in hydrocarbon greases. 

Caution. In common with other alkyldiarylphosphines, ethyldiphenylphosphine presents some hazard because of its toxicity and susceptibility to air oxidation. Therefore, all operations must be performed in an efficient hood with manipulations conducted under an inert atmosphere. All ground-glass joints should be greased thoroughly with a silicone lubricant. 

Use Stabilizing and rust-inhibiting agent for silicones, lubricant and fuel additive, polymerization catalyst, hydrogen chloride scavenger. 

Use Conditioning agent, manufacture of varnishes, alkyd resins, synthetic drying oils, urethane foams and coatings, silicone lubricant oils, lactone plasticizers, textile finishes, surfactants, epoxidation products. 

Grease films that are unaffected by cleaning solution may yield to such organic solvents as acetone or benzene. Thorough washing with detergent should follow such treatment. The use of silicone lubricants is not recommended contamination by such preparations is difficult—if not impossible—to remove. 

However, they are not used for yams that are dyed in the later process because silicone lubricants are difficult to remove, and silicones removed from the yams can deposit on the surface of machine parts, causing many processing problems. 

The most-used silicone lubricants in the fibre finishing applications are polydimethylsiloxane, polymethylphenylsiloxane, oleophilic silicone/organic copolymer (Fig. 5.7a), and poly(glycol silicone copolymer) (Fig. 5.7b). The analysis of silicones can be conducted by FTIR. A strong and often broad absorption in the 1000-1100 cm region can be attributed to the Si-O vibration. A peak at 1100 cm shows the Si-O-Si vibration. A sharp peak at 1260 cm" indicates the Si-( II. stretching absorption.- ... 

Chemical structures of the two most used silicone lubricants. 

The measurements of the viscoelastic properties were performed on a viscoanalyzer Metravib (R.D.S., Limonest, France) operating between 5 and 40 Hz, and between —50 and 180°C at a heating rate of l°Cmin . Samples were coafed with silicon lubricant and submitted to a deformation... 

Depending on stoppering equipment and tendency of stoppers to clump during sterilization, a silicone lubricant may be added to the stoppers prior to sterilization. Several manufacturers offer equipment which is capable of all these operations-washing, silicone addition, and sterilization. 

Dusil. [Ducey] Silicone dielectric compds. for elec, insulation, silicone lubricants, silicone heat sinks. 

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