Vinyl silicone

Ammonia Vinyl silicone 0.6% boric acid 0.4 ppm (8-hr exposure)... 

Some other silicon elastomers include vinyl silicone elastomers, phenyl silicon elastomers, nitrile silicone elastomers, and fluorosilicone elastomers. 

Fig. 1. SAE J200 Classification system for ASTM No. 3 oil where in volume swell nr = no requirement. EPDM is ethylene—propylene—diene monomer HR, butyl mbber SBR, styrene—butadiene mbber NR, natural mbber VMQ, methyl vinyl silicone CR, chloroprene FKM, fluoroelastomer FVMQ, fluorovinyl methyl silicone ACM, acrylic elastomers HSN, hydrogenated nitrile ECO, epichlorohydrin and NBR, nitrile mbber.

Silicone. Silicone elastomers have a siloxy backbone with methyl, vinyl, and phenyl groups attached. The elastomers are designated by their chemical composition, as follows methyl silicone (MQ), methyl vinyl silicone (VMQ), methyl phenyl silicone (PMQ), methyl phenyl vinyl silicone (PVMQ), and fluorovinyl methyl silicone (FVMQ). 

When vinyl silicon tnfluonde is treated with two equivalents of potassium fluonde, a new reagent, a dipotassium organopentafluorosilicate, is formed [101] This intermediate has found application as a component in an efficient stereoselective copper chlonde-promoted coupling reaction (equation 81)... 

Intramolecular anodic coupling of enol ethers to vinylsilanes generates carbon-carbon bonds while breaking the vinyl-silicon bond this may be used either to form new rings or to place a vinyl group where it is needed (Scheme 70)167. 

Polyester/cotton blends Polyester Polyurethane Vinyl Silicon Teflon... 

Most of the silicone rubbers used in the food industry are based on polydimethyl vinyl silicone and these materials have very good high- and low-temperature properties. It is their high-temperature resistance that enables them to be used for seals and tubing, for example, in drinks vending machines up to 100 °C. Cold cured silicones are used as release coatings on items such as food transportation belts and for sweet moulds. 

Figure 3 Common units found in silicone polymers (a) PDMS, (b) a methyl vinyl silicone monomer unit, and (c) a methyl hydrogen (silane) siloxane unit.

Vinylpyrrolidone/styrene copolymer. See Styrene/PVP copolymer Vinylpyrrolidone/vinyl acetate copolymer. See PVP/VA copolymer Vinylpyrrolidone/vinyl imidazolinium methochloride copolymer. See Polyquaternium-16 Vinyl silicon trichloride. See Vinyltrichlorosilane Vinyl stearate... 

Synonyms Silane, trichlorovinyl- Silane, vinyl trichloro- Trichloroethenylsilane (Trichlorosilyl) ethylene Trichlorovinylsilane Trichlorovinyl silicane Vinyl silicon trichloride Vinyl trichlorosilane, inhibited VTC Empirical C2H3CI Si Formula H2C=CHSiCl3... 

Silylative Coupling and Cross-Metathesis of Alkenes and Dienes with Vinyl-Silicon Derivatives — New Catalytic Routes to Synthesis of OrganosUicon Compounds ... 

Summary Recent achievements in two catalytic reactions, i.e., silylative coupling and cross-metathesis of alkenes and dienes with vinyl-silicon compounds, which resulted in new synthetic routes to organosilicon molecular and macromolecular compounds are presented. The silylative coupling, also called dehydrogenative or trans-silylation and silyl group transfer, is catalyzed by metal complexes which either contain or initiate the formation of M-H and M-Si bonds, where M = Ru, Rh, Co and Ir. Cross-metathesis, which was developed very recently, proceeds in the presence of metallacarbenes, mainly those of rathenium (e.g., Grabbs catalyst). 

Vinyl silicon compounds have been prepared by the direct reaction of vinyl chloride with elemental silicon and by... 

Vinylchlorosilanes are prepared most conveniently from ethylchlorosilanes by a modification of the chlorination-dehydrochlorination reactions in which the dehydrohalo-genation is effected by a high-boiling tertiary amine. Although the experimental procedure herein described is based on the preparation of vinyltrichlorosilane, the method can be adapted to the synthesis of many other vinyl silicon compounds. 

Vinyltrichlorosilane is a colorless, corrosive liquid boiling at 92°. Its specific gravity is 1.264 (27°/27°). It hydrolyzes in water or in moist air to form hydrogen chloride and an insoluble vinyl silicone gel. 

The mechanism of catalysis involves the insertion of the vinyl-silicon dienes into M-H and M-Si bond, followed by p-Si and P-H elimination, to yield ethene and two isomeric trans and gem- bis(vinylsilyl)ethenes respectively. In the presence of [RuCl2(CO)3] as a catalyst, rraw5-E-CH2=CH[Si]CH=CH[Si]CH=CH2 is exclusively formed [23]. Under optimum conditions the well-defined trans-iaciic (A) silylene (siloxylene)-vinylene (M = 6350-8650 M /Mn = 1.12-1.16) [23] and silazanylene-vinylene (Mw = 813) [18] polymers can be prepared. On the other hand, gem- dimeric products can be effectively formed with (B) when the reaction is catalyzed by [(cod)RuX]2 (where X = Cl, OSiMes) but finally intramolecular ring closure takes place to yield respective cyclotetrasiloxane, cyclotetrasilazane and cyclohexacarbosilanes [22]. 

Recent examples that have utilized the hydrosilylation reaction to prepare very imique organosiloxanes are shown in equations 4 and 5. Equation 4 depicts the hydrosilylation of phenylacetylene to provide beta-vinyl silicones (84,85) and is a convenient route to high refractive index silicones. 

Vinyl—silicon bonds are also rather easily cleaved by electrophiles. It appears that the R3Si group is able to stabilize //-carbonium ions. Allylsilanes are prone to attack even by fairly weak electrophiles. Acetals, aldehydes and ketones react in the presence of Lewis acids to form unsaturated alcohols. The reaction is accompanied by an allylic transposition ... 

Compared to dimethyl silicone elastomers, vinyl silicone elastomers have much reduced compression set. A further point is that although silicone elastomers are mostly reinforced with silica, special purpose electrically conducting elastomers are filled with carbon black. Carbon black does not inhibit cure by less active peroxides and may be used with vinyl silicone elastomers. This filler does, however, inhibit vulcanization by benzoyl peroxide (and its derivatives) and therefore cannot be added to dimethyl silicone gums. 

Vinyl groups have also been transferred to quaternary carbons using the vinyl silicon tether strategy. The vinylsiloxy ethers 21 were made by the reaction of the corresponding alcohols in DMF or DCM with chlorodimethylvinylsilane in the presence of pyridine or imidazole. They were subjected to radical reaction conditions using triethylborane to initiate the intramolecular cyclization followed by acid treatment to form the elimination products 22 favoring the 2,3-5 yw-diastereomer in good yields (eq 11). ... 

TABLE 1.61 VINYL, SILICONE AND FLUOROELASTOMER TUBING-BARNANT... 

---